Prosthetic valves, frames and leaflets and methods thereof

ABSTRACT

Described embodiments are directed toward prosthetic heart valve leaflets of particular shapes that control bending character. In accordance with an embodiment, a prosthetic heart valve comprises a leaflet frame having a generally tubular shape with attached film. The leaflet frame defines a plurality of leaflet windows. The film defines at least one leaflet extending from each of the leaflet windows. Each leaflet attachment zone on the leaflet frame has substantially the shape of an isosceles trapezoid having two leaflet sides, a leaflet base and a leaflet free edge opposite the leaflet base. The two leaflet sides diverge from the leaflet base, wherein the leaflet base is substantially flat.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/133,563, filed Dec. 18, 2013, which claims the benefit of U.S.Provisional Application 61/802,116, filed Mar. 15, 2013, and also claimsthe benefit of U.S. Application 61/739,721, filed Dec. 19, 2012, all ofwhich are incorporated herein by reference in their entireties for allpurposes.

FIELD

The present disclosure relates generally to prosthetic heart valves andmore specifically synthetic flexible leaflet-type prosthetic heart valvedevices, systems, and methods.

BACKGROUND

Bioprosthetic heart valves have been developed that attempt to mimic thefunction and performance of a native valve. Flexible leaflets arefabricated from biological tissue such as bovine pericardium. In somebioprosthetic heart valve designs, the biological tissue is sewn onto arelatively rigid frame that supports the leaflets and providesdimensional stability when implanted. Although bioprosthetic heartvalves can provide excellent hemodynamic and biomechanical performancein the short term, they are prone to calcification and cusp tears, amongother failure modes, requiring reoperation and replacement.

Attempts have been made to use synthetic materials, such aspolyurethane, among others, as a substitute for the biological tissue,to provide a more durable flexible leaflet prosthetic heart valve,herein referred to as a synthetic leaflet prosthetic heart valve (SLV).However, synthetic leaflet prosthetic heart valves have not become avalid heart valve replacement option since they suffer prematurefailure, due to, among other things, suboptimal design and lack of adurable synthetic material.

The leaflet moves under the influence of fluid pressure. In operation,the leaflets open when the upstream fluid pressure exceeds thedownstream fluid pressure and close when the downstream fluid pressureexceeds the upstream fluid pressure. The leaflet free edges of theleaflets coapt under the influence of downstream fluid pressure closingthe prosthetic heart valve to prevent downstream blood from flowingretrograde through the prosthetic heart valve.

Prosthetic heart valve durability under the repetitive loads of theleaflets opening and closing is dependent, in part, on the loaddistribution between the leaflet and the frame. Further, substantialload is encountered on the leaflet when in the closed position.Mechanical failure of the leaflet can arise, for example, at themounting edge, where the flexible leaflet is supported by the relativelyrigid frame. The repetitive loads of leaflet opening and closing leadsto material failure by fatigue, creep or other mechanism, depending inpart on the leaflet material. Mechanical failure at the mounting edge isespecially prevalent with synthetic leaflets.

The durability of the valve leaflets is also a function of the characterof bending by the leaflet during the opening-closing cycle. Small radiusbends, creases and intersecting creases, can produce high stress zonesin the leaflet. These high stress zones can cause the formation of holesand tears under repetitive loading.

Prosthetic heart valves may be delivered using surgical or transcathetertechniques. A surgical prosthetic heart valve is implanted into apatient using open-heart surgical techniques. The surgical prostheticheart valve is usually manufactured to have a fixed diameter as opposedto a transcatheter prosthetic heart valve which is required to attain arange of diameters for access and delivery. The surgical prostheticheart valve is usually provided with a sewing cuff about a perimeter ofthe prosthetic heart valve to allow for suturing to the native tissueorifice.

In addition to the prosthetic heart valve durability issues discussedabove, the transcatheter prosthetic heart valve must also be able towithstand the handling and deployment stresses associated with beingcompressed and expanded.

A preferred shape of synthetic prosthetic heart valve leaflets has beendescribed many times, but each is different from the others. The variousthree-dimensional shapes range from spherical or cylindrical totruncated conical intersections with spheres and an “alpharabola”.

The shape most often described as preferable is modeled after the nativehuman aortic valve. Though nature dictates the optimum shape for thenative tissues to form a heart valve, we have discovered this is nottrue for synthetic materials; accordingly, the design specified in thecurrent disclosure is instead intended to place the synthetic materialunder a minimized stress condition as compared to those based on copiesof the native valve. This is partially accomplished through reducedbuckling in the leaflet material.

SUMMARY

In accordance with an embodiment, a prosthetic valve comprises a leafletframe having a generally tubular shape, an outer frame having agenerally tubular shape, and a film. The term film as used hereingenerically refers to one or more of a membrane, composite material, orlaminate. The coaxially disposed at least partially within the outerframe. The leaflet frame and outer frame are coupled at least in part bya contiguous portion of the film. The leaflet frame defines a pluralityof leaflet windows, wherein the film defines a leaflet extending fromeach of the leaflet windows.

In accordance with another embodiment, a prosthetic valve comprises aleaflet frame having a generally tubular shape and an outer frame havinga generally tubular shape. The leaflet frame and outer frame are coupledtogether by a contiguous portion of a film in which the leaflet frame isnested into the outer frame in a telescoping manner. The leaflet framedefines a plurality of leaflet windows, wherein the film defines aleaflet extending from each of the leaflet windows.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe having a generally tubular shape, an outer frame having agenerally tubular shape, and film. The leaflet frame is coaxiallydisposed at least partially within the outer frame. The outer frameprovides frame elements that overlay leaflet windows that are defined bythe leaflet frame so as to provide structural support over the leafletwindows, as shown in FIGS. 1A-1B. The leaflet frame defines a pluralityof leaflet windows, wherein the film defines a leaflet extending fromeach of the leaflet windows.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe having a generally tubular shape, an outer frame having agenerally tubular shape, and film. The leaflet frame defines a pluralityof leaflet windows. The film defines at least one leaflet extending fromeach of the leaflet windows. Each leaflet has substantially the shape ofan isosceles trapezoid having two leaflet sides, a leaflet base and afree edge opposite the leaflet base. The two leaflet sides diverge fromthe leaflet base, wherein the leaflet base is substantially flat.

In accordance with other embodiments of the prosthetic valve, eachleaflet includes a central region and two side regions on opposite sidesof the central region. The central region is defined by a shapesubstantially that of an isosceles trapezoid defined by two centralregion sides, the leaflet base and the leaflet free edge. The twocentral region sides converge from the leaflet base. Each of the sideregions has a shape substantially that of a triangle and each aredefined by one of the central region sides, one of the leaflet sides,and the leaflet free edge.

In accordance with other embodiments of the prosthetic valve, eachleaflet includes a central region and two side regions on opposite sidesof the central region. The central region is defined by a shapesubstantially that of an isosceles triangle defined by two centralregion sides, the leaflet base and the leaflet free edge. The twocentral region sides converge from the leaflet base to the free edge.Each of the side regions has a shape substantially that of a triangleand each are defined by one of the central region sides, one of theleaflet sides, and the leaflet free edge. Each of the two side regionsand the central region are substantially planar when the valve is in theclosed position and under no pressure load.

In accordance with other embodiments of the prosthetic valve, the framecomprises a frame first end and a frame second end opposite the framefirst end, the leaflet window having a shape determined, at least inpart, by wrapping a two dimensional isosceles trapezoid onto the tubularshape of the frame, the isosceles trapezoid having a base and two sidesthat diverge from the base, and wherein a side from adjacent isoscelestrapezoids meet at the frame second end.

In accordance with other embodiments of the prosthetic valve, theleaflets defining a shape of a trapezoid wherein frame elements boundstwo sides, one side being a free edge, and the leaflet base being is ahorizontal truncation bound only by the film.

In accordance with other embodiments of the prosthetic valve, the filmdefining at least one leaflet is coupled to an outer surface of theleaflet frame.

In accordance with other embodiments of the prosthetic valve, the filmdefining at least one leaflet is coupled to an inner surface of theleaflet frame.

In accordance with other embodiments of the prosthetic valve, theleaflet frame and outer frame are coupled at least in part by acontiguous portion of the film.

In accordance with other embodiments of the prosthetic valve, the outerframe provides frame elements that overlay leaflet windows that aredefined by the leaflet frame so as to provide structural support overthe leaflet windows.

In accordance with other embodiments of the prosthetic valve, the outerframe provides frame elements that overlay the leaflet windows that aredefined by the leaflet frame, wherein the leaflet frame and outer framepresent a substantially uniform geometric pattern of frame elements thatact in concert so as to enable the frame assembly to compress and expandsubstantially uniformly when compressed and expanded for transcatheterapplications.

In accordance with other embodiments of the prosthetic valve, the filmis disposed between the leaflet frame and the outer frame.

In accordance with other embodiments of the prosthetic valve, theleaflet frame and outer frame are separated by the film and are not incontact with each other.

In accordance with other embodiments of the prosthetic valve, eachleaflet has a substantially flat leaflet base.

In accordance with other embodiments of the prosthetic valve, theleaflet frame defines three interconnected leaflet windows having asubstantially triangular shape.

In accordance with other embodiments the prosthetic valve comprises aleaflet frame having a generally tubular shape, an outer frame having agenerally tubular shape, and a film. The leaflet frame is coaxiallydisposed at least partially within the outer frame. The leaflet frameand outer frame are coupled at least in part by a contiguous portion ofthe film.

In accordance with other embodiments of the prosthetic valve, theleaflet frame defines a plurality of leaflet windows, and the filmdefines a leaflet extending from each of the leaflet windows.

In accordance with other embodiments of the prosthetic valve, a leafletwindow side of one leaflet window is interconnected with a leafletwindow side of an adjacent leaflet window.

In accordance with other embodiments of the prosthetic valve, eachleaflet has substantially the shape of an isosceles trapezoid having twoleaflet sides, a leaflet base and a free edge opposite the leaflet base,wherein the two leaflet sides diverge from the leaflet base, wherein theleaflet base is substantially flat.

In accordance with other embodiments of the prosthetic valve, theleaflet window is defined by window frame elements corresponding to theleaflet sides and leaflet base, wherein the film is coupled to thewindow frame elements and extends across the leaflet window defining theleaflet.

In accordance with other embodiments of the prosthetic valve, the filmextends across the leaflet window defining a bending region and asupport region separated by a bending interface, wherein the leafletbends within the bending region when cycled between an open and closedposition, wherein the bending interface defines the leaflet base andsides having substantially the shape of an isosceles trapezoid.

In accordance with other embodiments of the prosthetic valve, thebending interface is collocated with the leaflet window sides.

In accordance with other embodiments of the prosthetic valve, thebending interface is collocated with the leaflet window sides andleaflet window base.

In accordance with other embodiments of the prosthetic valve, thebending interface is spaced apart from and not collocated with theleaflet window base.

In accordance with other embodiments of the prosthetic valve, thebending interface is spaced apart from and not collocated with theleaflet window sides and leaflet window base.

In accordance with other embodiments of the prosthetic valve, thebending interface is collocated with a portion of the leaflet windowsides.

In accordance with other embodiments of the prosthetic valve, thebending interface defines the leaflet base and sides having the shape ofan isosceles trapezoid.

In accordance with other embodiments of the prosthetic valve, the framecomprises a plurality of spaced apart leaflet windows each definingsubstantially an isosceles triangle interconnected by a base element,wherein each leaflet window side is defined by a side of one triangleand a side of an adjacent triangle, and wherein each leaflet window baseis defined by the base element.

In accordance with other embodiments of the prosthetic valve, the framecomprises a base element and a plurality of spaced apart spade elementsinterconnected by the base element, wherein each leaflet window isdefined by a side of one spade element and a side of an adjacent spadeelement, and wherein each leaflet window base is defined by the baseelement.

In accordance with other embodiments of the prosthetic valve, the framecomprises a plurality of spaced apart interconnected leaflet windowseach defining substantially isosceles triangles, wherein each leafletwindow side is defined by a side of one triangle and a side of anadjacent triangle, and wherein each leaflet window base is defined bythe base element.

In accordance with other embodiments of the prosthetic valve, theprosthetic valve comprises a collapsed configuration and an expandedconfiguration for transcatheter delivery.

In accordance with other embodiments of the prosthetic valve, theleaflet is moveable between an open and closed position.

In accordance with other embodiments of the prosthetic valve, theleaflet comprises a polymeric film.

In accordance with other embodiments of the prosthetic valve, theleaflet comprises a laminate.

In accordance with other embodiments of the prosthetic valve, whereinthe laminate has more than one layer of a fluoropolymer membrane.

In accordance with other embodiments of the prosthetic valve, theleaflet comprises a film having at least one fluoropolymer membranelayer having a plurality of pores and an elastomer present insubstantially all of the pores of at least one layer of fluoropolymermembrane.

In accordance with other embodiments of the prosthetic valve, the filmcomprises less than about 80% fluoropolymer membrane by weight.

In accordance with other embodiments of the prosthetic valve, theelastomer comprises (per)fluoroalkylvinylethers (PAVE).

In accordance with other embodiments of the prosthetic valve, theelastomer comprises a copolymer of tetrafluoroethylene andperfluoromethyl vinyl ether.

In accordance with other embodiments of the prosthetic valve, thefluoropolymer membrane comprises ePTFE.

In accordance with other embodiments of the prosthetic valve, theleaflet frame and/or outer frame is defines a generally open pattern ofapertures operable to allow the outer frame to be compressed andexpanded between different diameters.

In accordance with other embodiments of the prosthetic valve, an aspectratio of a length of the valve to an diameter of the valve is less than1.

In accordance with other embodiments of the prosthetic valve, the valveis less than about 20 mm in length.

In accordance with other embodiments of the prosthetic valve, theleaflet frame and/or outer frame comprise a shape memory film.

In accordance with other embodiments of the prosthetic valve, theleaflet frame and/or outer frame comprises a metallic film.

In accordance with other embodiments of the prosthetic valve, in acollapsed configuration has a collapsed profile less than about 6 mm.

In accordance with other embodiments of the prosthetic valve, the valveis balloon expandable.

In accordance with other embodiments of the prosthetic valve, the filmsandwiches the outer frame and the leaflet frame.

In accordance with an embodiment, a prosthetic valve comprises aplurality of leaflets, each leaflet having a shape substantially that ofan isosceles trapezoid having two leaflet sides, a leaflet base, and afree edge opposite the leaflet base, wherein the two leaflet sidesdiverge from the leaflet base.

In accordance with another embodiment, a prosthetic valve comprises aplurality of leaflets, wherein, wherein each leaflet includes a centralregion and two side regions on opposite sides of the central region,wherein the central region is defined by a shape substantially that ofan isosceles triangle defined by two central region sides, the leafletbase and the leaflet free edge, wherein the two central region sidesconverge from the leaflet base, and wherein each of the side regionshave a shape substantially that of a triangle and each are defined byone of the central region sides, one of the leaflet sides, and theleaflet free edge.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe, an outer frame, and a film. The leaflet frame has a generallytubular shape defining a plurality of leaflet windows. The outer framehas a generally tubular shape. The leaflet frame is coaxially disposedat least partially within the outer frame. The leaflet frame and outerframe are coupled at least in part by a contiguous portion of the film.At least a portion of the contiguous portion of the film is containedbetween and coupling the leaflet frame and outer frame operable toprevent relative movement and contact therebetween. The film defines aleaflet extending from each of the leaflet windows.

In accordance with an embodiment, a prosthetic valve comprises andleaflet frame, and outer frame and a film. The leaflet frame has agenerally tubular shape defining a plurality of leaflet windows. Theouter frame has a generally tubular shape. The leaflet frame iscoaxially disposed at least partially within the outer frame. The outerframe includes frame elements that overlay the leaflet windows that aredefined by the leaflet frame in cooperative arrangement so as to providestructural support over the leaflet windows. The film defines a leafletextending from each of the leaflet windows.

In accordance with an embodiment, a method of making a prosthetic valve,comprises: wrapping a first layer of film into a tubular form about amandrel;

providing a leaflet frame having a generally tubular shape, the leafletframe having a leaflet frame leaflet surface and a leaflet frame outersurface, the leaflet frame defining a plurality of leaflet windowshaving a window top; providing an outer frame having a generally tubularshape, the outer frame having an outer frame leaflet surface and anouter frame outer surface; placing the leaflet frame and the outer frameover the first layer of film with the leaflet frame and outer framespaced apart from each other defining a bridge portion therebetween, theleaflet frame inner surface and the outer frame inner surface in contactwith the first layer of film;

forming a second layer of film over the leaflet frame and the outerframe in contact with the leaflet frame outer surface and the outerframe outer surface; coupling the first layer of film and the secondlayer of film to each other and to the leaflet frame and the outerframe; cutting the first layer of film and the second layer of filmacross the window top within the leaflet window so as to define aleaflet free edge; masking with release material a portion of the filmdisposed in the leaflet window that defines the leaflet to preventfurther bonding of the leaflet during subsequent processing steps;wrapping a third layer of film into a tubular form over the second layerof film and over the release material that is over the leaflet window,overlapping the leaflet frame, the outer frame, and over the bridgeportion between the leaflet frame and outer frame; coupling the thirdlayer of film and the second layer of film to each other;

removing the assembly from the mandrel; disposing coaxially and at leastpartially the leaflet frame into the outer frame, folding andoverlapping at least partially the bridge portion so as to contain thebridge portion between the leaflet frame and the outer frame; placingthe assembly back on the mandrel; coupling the bridge portion to itselfand to the third layer of film adjacent the leaflet frame outer surfaceand the first layer adjacent the outer frame inner surface in nestingengagement.

Described embodiments are directed to an apparatus, system, and methodsfor valve replacement, such as cardiac valve replacement. Morespecifically, described embodiments are directed toward flexible leafletvalve devices in which the leaflets are divided into zones, each with aparticular geometry.

In accordance with an embodiment, a prosthetic valve comprises aplurality of leaflets, each leaflet defining two side regions and acentral region between the side regions, the central region having ashape that is different from that of the side regions.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe and a film. The leaflet frame has a generally tubular shape. Theleaflet frame defines a plurality of leaflet windows wherein each of theleaflet windows includes two leaflet window sides, a leaflet windowbase, and a leaflet window top. The film being coupled to the leafletframe and defining at least one leaflet extending from each of theleaflet windows, wherein each leaflet has substantially the shape of anisosceles trapezoid having two leaflet sides, a leaflet base and a freeedge opposite the leaflet base, wherein the two leaflet sides divergefrom the leaflet base, and wherein the leaflet base is substantiallyflat. The leaflet base is coupled to the window base and each of the twoleaflet sides are coupled to one of the two window sides.

In accordance with an embodiment, a prosthetic valve comprises aplurality of leaflets. Each leaflet includes a central region and twoside regions on opposite sides of the central region. The central regionis defined by a shape substantially that of an isosceles triangledefined by two central region sides, the leaflet base and the leafletfree edge, wherein the two central region sides converge from theleaflet base, and wherein each of the side regions have a shapesubstantially that of a triangle and each are defined by one of thecentral region sides, one of the leaflet sides, and the leaflet freeedge.

In accordance with an embodiment, a method of forming a prosthetic heartvalve comprises providing a leaflet frame having a generally tubularshape, the leaflet frame defining a plurality of leaflet windows whereineach of the leaflet windows includes two leaflet window sides, a leafletwindow base, and a leaflet window top; providing a film, and wrappingthe film about the leaflet frame bringing more than one layer of thefilm into contact with additional layers of the film defining at leastone leaflet extending from each of the leaflet windows, wherein eachleaflet has substantially the shape of an isosceles trapezoid having twoleaflet sides, a leaflet base and a free edge opposite the leaflet base,wherein the two leaflet sides diverge from the leaflet base, wherein theleaflet base is substantially flat; wherein the leaflet base is coupledto the window base and wherein each of the two leaflet sides are coupledto one of the two window sides providing a generally annular supportstructure; and bonding the layers of film to itself and to the leafletframe.

In accordance with an embodiment, a method of forming a prosthetic heartvalve comprises providing a leaflet frame having a generally tubularshape, the leaflet frame defining a plurality of leaflet windows whereineach of the leaflet windows includes two leaflet window sides, a leafletwindow base, and a leaflet window top; providing a film; wrapping thefilm about the leaflet frame bringing more than one layer of the filminto contact with additional layers of the film defining at least oneleaflet extending from each of the leaflet windows, wherein each leaflethas substantially the shape of an isosceles trapezoid having two leafletsides, a leaflet base and a free edge opposite the leaflet base, whereinthe two leaflet sides diverge from the leaflet base, wherein the leafletbase is substantially flat; wherein the leaflet base is coupled to thewindow base and wherein each of the two leaflet sides are coupled to oneof the two window sides providing a generally annular support structure;and bonding the layers of film to itself and to the leaflet frame.

Described embodiments are directed to an apparatus, system, and methodsfor valve replacement, such as cardiac valve replacement. Morespecifically, described embodiments are directed toward flexible leafletvalve devices in which a truncated segment at the base of the leaflet ispresent at or adjacent to the intersection with the frame.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe, a plurality of leaflets that are coupled to the leaflet frame,where each leaflet has a free edge and a base. The base of each leafletis truncated in which the leaflet in cross section shows a line in analpha plane onto the leaflet frame.

In accordance with an embodiment, a prosthetic valve comprises a framehaving a generally tubular shape with attached film. The frame defines aplurality of leaflet windows. The film defines at least one leafletextending from each of the leaflet windows. Each leaflet two leafletsides, a planar central zone, a leaflet base and a free edge oppositethe leaflet base. The two leaflet sides diverge from the leaflet base.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe, a plurality of leaflets that are coupled to the leaflet frame,where each leaflet has a free edge and a base. Each leaflet has a planarzone in a central portion, wherein the planar zone is substantiallyplanar. The planar zone defines a shape having an area, wherein the areais larger nearer the base than the free edge.

In accordance with an embodiment, a prosthetic heart valve comprises aleaflet frame having a generally tubular shape with attached film. Theleaflet frame defines a plurality of leaflet windows. The film definesat least one leaflet extending from each of the leaflet windows. Eachleaflet attachment zone on the leaflet frame has substantially the shapeof an isosceles trapezoid having two leaflet sides, a leaflet base and aleaflet free edge opposite the leaflet base. The two leaflet sidesdiverge from the leaflet base, wherein the leaflet base is substantiallyflat.

In accordance with other embodiments of the prosthetic heart valve, eachleaflet attachment zone on the leaflet frame includes a central regionand two side regions on opposite sides of the central region. Thecentral region of the attachment zone on the leaflet frame is defined bya shape substantially that of an isosceles trapezoid defined by twocentral region sides, the leaflet base and the leaflet free edge. Thetwo central region sides of the attachment zone on the leaflet frameconverge from the leaflet base. Each of the side regions of theattachment zone on the leaflet frame has a shape substantially that of atriangle and each are defined by one of the central region sides, one ofthe leaflet sides, and the leaflet free edge.

In accordance with other embodiments of the prosthetic heart valve, eachleaflet attachment zone on the leaflet frame includes a central regionand two side regions on opposite sides of the central region. Thecentral region of the attachment zone on the leaflet frame is defined bya shape substantially that of an isosceles triangle defined by twocentral region sides, the leaflet base and the leaflet free edge. Thetwo central region sides converge from the leaflet base to the leafletfree edge. Each of the side regions of the attachment zone on theleaflet frame has a shape substantially that of a triangle and each aredefined by one of the central region sides, one of the leaflet sides,and the leaflet free edge.

In accordance with other embodiments of the prosthetic heart valve, theleaflet frame comprises a leaflet frame first end and a leaflet framesecond end opposite the leaflet frame first end, the leaflet windowhaving a shape determined, at least in part, by wrapping a twodimensional isosceles trapezoid pattern onto the tubular shape of theleaflet frame, the isosceles trapezoid pattern having a base and twosides that diverge from the base, and wherein a side from adjacentisosceles trapezoids meet at the leaflet frame second end.

In accordance with other embodiments of the prosthetic heart valve, theleaflets defining a shape of a trapezoid wherein frame elements boundstwo sides, one side being a leaflet free edge, and the leaflet basebeing is a horizontal truncation bound only by the film.

In accordance with an embodiment, a prosthetic heart valve comprises aplurality of leaflets, each leaflet attachment zone on the leaflet framehaving a shape substantially that of an isosceles trapezoid having twoleaflet sides of the attachment zone on the leaflet frame, a leafletbase, and a leaflet free edge opposite the leaflet base, wherein the twoleaflet sides diverge from the leaflet base.

In accordance with another embodiment, a prosthetic heart valvecomprises a plurality of leaflets, wherein, wherein each leafletattachment zone on the leaflet frame includes a central region and twoside regions on opposite sides of the central region, wherein thecentral region is defined by a shape substantially that of an isoscelestriangle defined by two central region sides, the leaflet base and theleaflet free edge, wherein the two central region sides converge fromthe leaflet base, and wherein each of the side regions of the attachmentzone on the leaflet frame have a shape substantially that of a triangleand each are defined by one of the central region sides, one of theleaflet sides, and the leaflet free edge.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure and are incorporated in andconstitute a part of this specification, illustrate embodimentsdescribed herein, and together with the description serve to explain theprinciples discussed in this disclosure.

FIG. 1A is a side view of an embodiment of a prosthetic heart valve;

FIG. 1B is a side view of the embodiment of the prosthetic heart valveof FIG. 1A that is partially rotated about the axis X;

FIG. 1C is a perspective view of the embodiment of the prosthetic heartvalve of FIG. 1A;

FIG. 1D is a representation of a prosthetic heart valve in an expandedconfiguration;

FIG. 1E is a representation of a prosthetic heart valve in a compressedconfiguration;

FIG. 2A is a representation of the embodiment of the prosthetic heartvalve of FIG. 1A unrolled to a flat orientation;

FIG. 2B is an exploded representation of the embodiment of theprosthetic heart valve of FIG. 1A unrolled to a flat orientation;

FIG. 3A is an axial or top view of the embodiment of the prostheticheart valve of FIG. 1A in an open configuration;

FIG. 3B is an axial or top view of the embodiment of the prostheticheart valve of FIG. 1A in a closed configuration;

FIG. 4A is a side view of an embodiment of a transcatheter deliverysystem within anatomy;

FIG. 4B is a side view of an embodiment of a surgical prosthetic heartvalve within anatomy;

FIG. 5A is a cross-sectional view of an embodiment of the valve duringmanufacture;

FIG. 5B is a cross-sectional view of the leaflet frame and the outerframe as nested together, in accordance with the embodiment of FIG. 5A;

FIG. 6A is an embodiment of an outer frame unrolled to a flatorientation;

FIG. 6B is an embodiment of an outer frame unrolled to a flatorientation;

FIG. 7A is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 7B is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 8A is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 8B is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 8C is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 8D is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 8E is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 8F is an embodiment of a leaflet frame unrolled to a flatorientation;

FIG. 9A is a side view of a leaflet frame and an outer frame on anassembly mandrel, in accordance with an embodiment;

FIG. 9B is a side view of the leaflet frame and the outer frame asnested together on an assembly mandrel, in accordance with theembodiment of FIG. 9A;

FIG. 10A is a side exploded view of a leaflet frame and an outer framethat may be coupled by a mechanical engagement member, in accordancewith another embodiment;

FIG. 10B is a side view of an assembled embodiment of FIG. 10A;

FIG. 11A is a side view of an embodiment of a prosthetic heart valve;

FIG. 11B is a perspective view of the embodiment of the prosthetic heartvalve of FIG. 11A;

FIG. 11C is an axial or top view of the embodiment of the prostheticheart valve of FIG. 11A in an open configuration;

FIG. 11D is an axial or top view of the embodiment of the prostheticheart valve of FIG. 1A in a closed configuration;

FIG. 12 is a side view of a leaflet frame on an assembly mandrel, inaccordance with an embodiment of FIGS. 11A and 11B;

FIG. 13A is a side view of the leaflet frame on a cutting mandrel, inaccordance with an embodiment;

FIG. 13B is a perspective view of the leaflet frame on the cuttingmandrel of FIG. 13A;

FIG. 14 is an axial view of an embodiment of a prosthetic heart valve inan open configuration;

FIG. 15 is an axial view of an embodiment of a prosthetic heart valve inan open configuration;

FIG. 16A is a representation of an aortic valve; and

FIG. 16B is a cross-section of the aortic valve of FIG. 16A showing theangles associated with a leaflet heart valve.

DETAILED DESCRIPTION

Persons skilled in the art will readily appreciate that various aspectsof the present disclosure can be realized by any number of methods andapparatus configured to perform the intended functions. Stateddifferently, other methods and apparatuses can be incorporated herein toperform the intended functions. It should also be noted that theaccompanying drawing figures referred to herein are not necessarilydrawn to scale, but may be exaggerated to illustrate various aspects ofthe present disclosure, and in that regard, the drawing figures shouldnot be construed as limiting.

Although the embodiments herein may be described in connection withvarious principles and beliefs, the described embodiments should not bebound by theory. For example, embodiments are described herein inconnection with prosthetic heart valves, more specifically cardiacprosthetic heart valves. However, embodiments within the scope of thisdisclosure can be applied toward any heart valve or mechanism of similarstructure and/or function. Furthermore, embodiments within the scope ofthis disclosure can be applied in non-cardiac applications.

The term leaflet as used herein in the context of prosthetic heartvalves is a component of a one-way valve wherein the leaflet is operableto move between an open and closed position under the influence of apressure differential. In an open position, the leaflet allows blood toflow through the prosthetic heart valve. In a closed position, theleaflet substantially blocks retrograde flow through the prostheticheart valve. In embodiments comprising multiple leaflets, each leafletcooperates with at least one neighboring leaflet to block the retrogradeflow of blood. The pressure differential in the blood is caused, forexample, by the contraction of a ventricle or atrium of the heart, suchpressure differential typically resulting from a fluid pressure buildingup on one side of the leaflets when closed. As the pressure on an inflowside of the prosthetic heart valve rises above the pressure on theoutflow side of the prosthetic heart valve, the leaflets open and bloodflows therethrough. As blood flows through the prosthetic heart valveinto a neighboring chamber or blood vessel, the pressure on the inflowside equalizes with the pressure on the outflow side. As the pressure onthe outflow side of the prosthetic heart valve rises above the bloodpressure on the inflow side of the prosthetic heart valve, the leafletreturns to the closed position generally preventing retrograde flow ofblood through the prosthetic heart valve.

The term membrane as used herein refers to a sheet of materialcomprising a single composition, such as, but not limited to, expandedfluoropolymer.

The term composite material as used herein refers to a combination of amembrane, such as, but not limited to, expanded fluoropolymer, and anelastomer, such as, but not limited to, a fluoroelastomer. The elastomermay be imbibed within a porous structure of the membrane, coated on oneor both sides of the membrane, or a combination of coated on and imbibedwithin the membrane.

The term laminate as used herein refers to multiple layers of membrane,composite material, or other materials, such as elastomer, andcombinations thereof.

The term film as used herein generically refers to one or more of themembrane, composite material, or laminate.

The term leaflet window is defined as that space that a leaflet framedefines from which a leaflet extends. The leaflet may extend fromleaflet frame elements or adjacent to and spaced apart therefrom.

The term frame element as used herein refers to any portion of a leafletframe or outer frame, such as, but not limited to, those individualportions that define a leaflet window or aperture.

The term attachment zone as used herein refers to the portion of thefilm that is attached to something so as to define the shape of theleaflet. The attachment zone may be, such as, but not limited to, thatportion of the film that is coupled to the frame elements that definethe leaflet window. The attachment zone may also be, such as, but notlimited to, that portion of the film that is coupled to another film ata location that is not directly adjacent to a frame element.

The terms native heart valve orifice and tissue orifice refer to ananatomical structure into which a prosthetic heart valve may be placed.Such anatomical structure includes, but is not limited to, a locationwherein a cardiac valve may or may not have been surgically removed. Itis understood that other anatomical structures that may receive aprosthetic heart valve include, but are not limited to, veins, arteries,ducts and shunts. Although reference is made herein to replacing anative heart valve with a prosthetic heart valve, it is understood andappreciated that a valve orifice or implant site may also refer to alocation in a synthetic or biological conduit that may receive a valvefor a particular purpose, and therefore the scope of the embodimentsprovided herein is not limited to heart valve replacement.

As used herein, “couple” means to join, connect, attach, adhere, affix,or bond, whether directly or indirectly, and whether permanently ortemporarily.

As used herein, truncated or truncation refers to the sectioning of athree-dimensional body with a plane reducing the size of the body.Referring to FIGS. 1A and 3B, a truncation zone is that area of theleaflet that may be truncated by a truncation plane intersecting thealpha plane so as to define an attachment line, i.e., a line ofattachment, of the leaflet base.

Embodiments herein include various apparatus, systems, and methods for aprosthetic heart valve suitable for surgical and transcatheterplacement, such as, but not limited to, cardiac valve replacement. Theprosthetic heart valve is operable as a one-way valve wherein theprosthetic heart valve defines a valve orifice into which leaflets opento permit flow and close so as to occlude the valve orifice and preventflow in response to differential fluid pressure.

Embodiments provided herein are related to controlled leaflet opening.The durability of the prosthetic heart valve leaflets is largelycontrolled by the character of bending exhibited by the leaflet duringthe opening-closing cycle. Small radius bends, creases and particularlyintersecting creases, can produce high stress zones in the leaflet.These high stress zones can cause the formation of holes and tears underrepetitive loading.

Controlled bending is of particular importance in thin, high-modulussynthetic leaflets, since the bending in these materials tends to becellophane-like. If the leaflet bending character is uncontrolled, notonly do creases form, but crease intersections lead to formation oflarge three dimensional structures that oppose bending and slow down theleaflet motion, both in opening and closing: in order to avoid this, thesequence of opening of the parts of the leaflet must be controlled.

Controlled bending is achieved through a particular frame shape, inaccordance with embodiments. The frame shape dictates the leafletattachment perimeter, which further dictates leaflet movement.

Embodiments provided herein present advancement in prosthetic heartvalve technology related to, but not limited to, mechanic and biologicalperformance advantages. In accordance with some embodiments presentedherein, a prosthetic heart valve comprises two frames, a leaflet frameand an outer frame, that are coupled together by a contiguous film inwhich a leaflet frame is nested into an outer frame in a telescopingmanner, wherein there is no chance for the prosthetic heart valve toleak between the leaflet frame and the outer frame.

In accordance with some embodiments presented herein, a prosthetic heartvalve comprises two frames; a leaflet frame and an outer frame. The filmthat comprises the leaflet may be coupled to the inner surface of theleaflet frame. In some other embodiments, the film that comprises theleaflet is contained between the leaflet frame and the outer frame andextends through a leaflet window defined by the leaflet frame. Theleaflet, therefore, is significantly prevented from peeling ordelaminating as it is contained between the leaflet frame and outerframe, as compared to where the leaflets are only coupled to the innersurface of the leaflet frame.

In accordance with some embodiments presented herein, a prosthetic heartvalve comprises two frames; a leaflet frame and an outer frame. Theleaflet frame and the outer frame are separated from each other by afilm. In other words, there is a metal to polymer to metalinterconnection, wherein there is no metal to metal contact between theleaflet frame and the outer frame.

In accordance with some embodiments presented herein, a prosthetic heartvalve comprises two frames; a leaflet frame and an outer frame. Theleaflet frame is nested within the outer frame, wherein the leafletframe and outer frame cooperate to provide relatively high resistance toflat plate compression, among other things. In accordance with someembodiments, the outer frame provides frame elements that overlay theleaflet windows that are defined by the leaflet frame so as to providestructural support over the leaflet windows. In accordance with someembodiments, the outer frame provides frame elements that overlay theleaflet windows that are defined by the leaflet frame so as to preventtissue from extending into the leaflet windows when implanted. Inaccordance with some embodiments, the outer frame provides frameelements that overlay the leaflet windows that are defined by theleaflet frame and act in concert so as to allow the frame assembly tocompress and expand uniformly for transcatheter embodiments.

In accordance with some embodiments presented herein, a prosthetic valvecomprises two frames; a leaflet frame and an outer frame. The leafletframe defines leaflet windows that define, in part, the shape of theleaflets. In some embodiments the leaflet comprises a flat base, whereinthe leaflet bends from the base towards the leaflet free edge withminimal creasing and fluttering. In some embodiments the leafletcomprises a flat base, that, among other things, that provides for oneor more of a shorter valve length, substantially prevents bloodstagnation and pooling and encourages washing at the base, as comparedto leaflets having a rounded base.

In accordance with some embodiments presented herein, a prosthetic valvecomprises two frames; a leaflet frame and an outer frame. The leafletframe defines leaflet windows from which the leaflets extend. Theleaflets are defined by the intersection of films that form anoverlapping zone so as to define, at least in part, the leaflet baseand/or the leaflet sides.

The length of a leaflet heart valve is dictated by the angle the leafletmakes with respect to the enclosing frame. A longer leaflet has ashallower angle with respect to the frame. A shorter leaflet has asteeper angle with respect to the frame. A longer leaflet leads tobetter performance than a shorter leaflet. For most applicationshowever, only a short valve can fit into the recipient location. Thusthe valve designer is presented with a dilemma. In the instantembodiments, leaflet designs are provided that provide for goodperformance with a short leaflet, thus allowing short heart valves.

Embodiments provided herein place the synthetic materials under aminimized stress condition as compared to those based on copies of thenative valve. This is partially accomplished through reduced buckling inthe leaflet material.

Embodiments provided herein address controlled leaflet opening. Thedurability of the valve leaflets is largely controlled by the characterof bending exhibited by the leaflet during the opening-closing cycle.Small radius bends, creases and particularly intersecting creases, canproduce high stress zones in the leaflet. These high stress zones cancause the formation of holes and tears under repetitive loading.Embodiments provided herein provide a feature of leaflet shape so as tominimize crease formation, which is of particular importance in thin,high-modulus leaflets, since the bending in these materials tends to becellophane-like. If the leaflet bending is unrestricted, not only docreases form, but crease intersections lead to formation of large threedimensional structures that oppose bending and slow down the leafletmotion, both in opening and closing. Embodiments provided herein controlleaflet opening and provide minimization of crease formation provided byan inclusion of a planar zone in the leaflet.

Prosthetic Heart Valve

FIG. 16A is a sketch of an aortic valve 5. The leaflets 1 are coupled tothe aortic root 2 at the leaflet base 3. FIG. 16B is a cross-section ofthe aortic valve 5 of FIG. 16A showing the angles associated with aleaflet 1 of the aortic valve 5. FIG. 16B illustrates the relationshipbetween the leaflets 1 and a first horizontal line L1 extending throughthe leaflet base 3 at an attachment point 7, and a second horizontalline L2 extending through the tops 4 of the commissure. In FIG. 16B, theaortic valve 5 is oriented in a position with a valve axis X beingvertical, the inflow edge 6 is pointed downward, with the leaflets 1 inthe closed position. The attachment angle alpha (α) is defined as theangle between the tangent line Lt extending from the center of theleaflet base 3 of the leaflet 1 at the attachment point 7 and the firsthorizontal line L1 extending through the leaflet base 3 at theattachment point 7, as shown in FIG. 16A.

Referring to FIG. 16B: Rb is the radius of the base, Rc is the radius ofthe commissures, H is the valve height, alpha is the bottom surfaceangle of the leaflet, phi is the free edge angle of the leaflet, Hs isthe height of the commissures, and Cc is the coaptation height.

It is understood that leaflets 1 may exhibit a concave, straight, orconvex shape in an axial cross-section through the center of the leafletbase 3 of the leaflet 1 at the attachment point 7. For the sake ofclarity and simplification of description of the embodiments presentedherein and not limited thereto, the geometry of a leaflet 1 is describedas having, in an axial cross-section through the center of the leafletbase 3 of the leaflet 1 at the attachment point 7, the tangent line Ltthat defines a as a straight line.

Embodiments provided herein provide a solution to the tension betweendesiring a small alpha angle to have a short valve and a larger alphaangle resulting in longer leaflets for better leaflet bending behavior.Embodiments provided herein provide a larger alpha angle while reducingvalve length, by providing a leaflet that wherein the leaflet base 3 istruncated, providing a relatively flat leaflet base 143.

In accordance with embodiments herein, the attachment angle alpha (α) ofa given valve configuration is preserved as the leaflet height isreduced. This is accomplished by redefining the base of the leaflet notas an attachment point 3 as for the generally parabolic leaflet shape asshown in FIG. 1A, but as an attachment line 8 as shown in FIG. 3B, thatis parallel to the horizontal line in the valve cross sectional planeperpendicular to the valve axis X at the leaflet base 143 of the leaflet140.

As a way to visualize embodiments provided herein, referring to FIG.16B, the first horizontal line L1 extends through the leaflet base 3 aas it moves perpendicular along the valve axis X towards the commissuretops 4. A plane containing the first horizontal line L1 andperpendicular to the valve axis, referred to as the alpha plane,intersects the leaflet frame 140 of FIG. 1A along a line. Wherein theleaflet base 7 is truncated by the alpha plane, wherein the attachmentpoint 3 of the leaflet base 7 becomes an attachment line 144, that is, aline of attachment rather than a point, of the leaflet base 143 as shownin FIGS. 1A and 3B.

Referring to FIG. 3B, an apex line La is indicated connecting the apices147 of the leaflets 140. The apex line La divides the leaflet 140 into afirst region 149 a adjacent the leaflet frame 130, and a second region149 b adjacent the leaflet free edge. The first region 149 a defines atruncated zone. The truncated zone is located on the lower section ofthe leaflet 140 adjacent the leaflet base 143. Referring to FIGS. 1A and3B, the truncation zone is that area of the leaflet 140 that may betruncated by a truncation plane intersecting the alpha plane so as todefine an attachment line 144, i.e., a line of attachment, of theleaflet base 143.

FIG. 1A is a side view of a prosthetic heart valve 100, in accordancewith an embodiment. FIG. 1B is also a side view of the prosthetic heartvalve 100 of FIG. 1A rotated 60 degrees about the longitudinal axis X.FIG. 1C is a perspective view of the prosthetic heart valve 100 of FIG.1A. FIG. 2A is a side view of the prosthetic heart valve 100 of FIG. 1Awherein the prosthetic heart valve 100 has been longitudinally cut andlaid open to better illustrate the elements of the generallytubular-shaped prosthetic heart valve 100. FIG. 2B is an exploded viewof the embodiment of FIG. 2A. FIGS. 3A and 3B are axial views of theprosthetic heart valve 100 of FIG. 1A in an open and closedconfiguration, respectively. In FIG. 3B the leaflets 140 are shownslightly open to better show the features but it is understood that afully closed prosthetic heart valve 100 will have the leaflet free edges142 of the leaflets 140 coming together to coapt under the influence ofdownstream fluid pressure which results in closing the valve to preventdownstream blood from flowing retrograde through the valve.

The valve 100 comprises an outer frame 120, a leaflet frame 130, and afilm 160 covering the outer frame 120 and leaflet frame 130, couplingthe outer frame 120 to the leaflet frame 130, and defining leaflets 140.The embodiment of valve 100 is discussed further related to atranscatheter valve that may be compressed and re-expanded. It isunderstood that the embodiment of valve 100 is also applicable to asurgical valve by the addition of a sewing cuff 170 as shown in FIG. 4B.Leaflet frame and outer frame configurations related to surgical valveonly embodiments where the valves have a fixed diameter, will bediscussed in other embodiments later in this disclosure.

In accordance with an embodiment, a prosthetic valve comprises a leafletframe 130 having a generally tubular shape, an outer frame 120 having agenerally tubular shape, and film 160. The leaflet frame 130 iscoaxially disposed at least partially within the outer frame 120. Theouter frame 120 provides frame elements that overlay leaflet windowsthat are defined by the leaflet frame 130 so as to provide structuralsupport over the leaflet windows, as shown in FIGS. 1A-1B. The leafletframe 130 defines a plurality of leaflet windows, wherein the film 160defines a leaflet extending from each of the leaflet windows.

11A is a side view of a prosthetic heart valve 200, in accordance withan embodiment. FIG. 11B is a perspective view of the prosthetic heartvalve 200 of FIG. 1A. The prosthetic heart valve 200 comprises a leafletframe 130 f and film 160 that defines leaflets 140. In FIGS. 3B and 11D,the leaflets 140 are shown slightly open to better show the features butit is understood that a fully closed prosthetic heart valve 200 willhave the leaflet free edges 142 of the leaflets 140 coming together tocoapt under the influence of downstream fluid pressure which results inclosing the valve to prevent downstream blood from flowing retrogradethrough the valve. The term “frame element” as used herein refers to anyportion of the leaflet frame 130, such as, but not limited to, thoseindividual portions that define a leaflet window 137. The leaflet framefirst end 131 a further comprises commissure posts 136 extending from anapex of the leaflet frame elements defining substantially a triangle.

FIG. 8D is a side view of the leaflet frame 130 f of the prostheticheart valve 200 of FIGS. 11A and 11B wherein the leaflet frame 130 f hasbeen longitudinally cut and laid open to better illustrate the elementsof the generally tubular-shaped prosthetic heart valve 200. The leafletframe 130 f comprises a plurality of spaced apart frame elements 139defining substantially an isosceles triangles interconnected by a baseelement 138 f defining leaflet windows 137 f having the shape of andisosceles trapezoid. Each leaflet window side 133 is defined by a sideof one triangle and a side of an adjacent triangle, and wherein eachleaflet window base 134 is defined by the base element 138. The term“frame element” as used herein refers to any portion of the leafletframe 130, such as, but not limited to, those individual portions thatdefine a leaflet window 137.

Referring again to FIGS. 11A and 8D, the leaflet frame first end 131 afurther comprises commissure posts 136 extending from an apex of theleaflet frame elements defining substantially an isosceles triangle. Thecommissure post 136 may affect the leaflet free edge 142 so as to createa larger or wider coaptation region 146 between adjacent leaflet freeedges 142.

Outer Frame

The outer frame 120 is a generally tubular member defining a generallyopen pattern of apertures 122, in accordance with an embodiment, asshown in FIG. 1C. The outer frame 120 is comprised of a generallycylindrical arrangement of three triangular-shaped leaflet windows 137,the centers of which are each spaced apart by 120°, as shown in FIG. 2B.

In accordance with transcatheter embodiments, the outer frame 120 isoperable to allow it to be compressed and expanded between differentdiameters. The outer frame 120 comprises an outer frame outer surface126 a and an outer frame inner surface 126 b opposite the outer frameouter surface 126 a, as shown in FIG. 5A. The outer frame 120 maycomprise a structure known in the art as a stent. A stent is a tubularmember that may have a small diameter suitable for percutaneoustranscatheter delivery into the anatomy, and may be expanded to a largerdiameter when deployed into the anatomy. Stents having various designsand material properties are well known in the art.

By way of example, and as illustrated in the embodiments of FIGS. 1A-1Cand 2A-2B, the prosthetic heart valve 100 includes the outer frame 120that defines a stent having apertures 122 having generally a diamondshape when in a large diameter configuration, as shown generally in FIG.1D. Upon compression to a smaller diameter, the apertures 122 deform togenerally define an elongated diamond shape, as shown generally in FIG.1E. Upon re-expansion to a larger diameter, the apertures 122 re-expandto again define a generally diamond shape.

As shown in FIGS. 5A and 5B, both views showing the elements incross-section, the leaflet frame 130 has a generally tubular shapedefining a plurality of leaflet windows (not shown). The outer frame 120has a generally tubular shape. The leaflet frame 130 is coaxiallydisposed at least partially within the outer frame 120. The leafletframe 130 and outer frame 120 are coupled at least in part by acontiguous portion of the film 160. At least a portion of the contiguousportion of the film 160 is contained between and couples the leafletframe 130 to the outer frame 120 to inhibit relative movementtherebetween. The film defines a leaflet 140 extending from each of theleaflet windows. The leaflet base 143 is defined at a fold line 145 inthe film 160. In accordance with an embodiment, at least a portion ofthe contiguous portion of the film 160 that is contained between andcoupling the leaflet frame 130 and outer frame 120 prevents contactbetween the leaflet frame 130 and outer frame 120.

FIGS. 6A and 6B are side views of alternative embodiments of the outerframe 120 a, 120 b wherein the outer frame has been longitudinally cutand laid open to better illustrate the elements of the outer frame.

An open framework of the stent can define any number of features,repeatable or otherwise, such as geometric shapes and/or linear ormeandering series of sinusoids. Geometric shapes can comprise any shapethat facilitates substantially uniform circumferential compression andexpansion. The outer frame 120 may comprise a cut tube, or any otherelement suitable for the particular purpose. The outer frame 120 may beetched, cut, laser cut, or stamped into a tube or a sheet of material,with the sheet then formed into a substantially cylindrical structure.Alternatively, an elongated material, such as a wire, bendable strip, ora series thereof, can be bent or braided and formed into a substantiallycylindrical structure wherein the walls of the cylinder comprise an openframework that is compressible to a smaller diameter in a generallyuniform and circumferential manner and expandable to a larger diameter.

It is known that stents of various designs may be elastically deformableso as to be self-expanding under spring loads. It is also known thatstents of various designs may be plastically deformable so as to bemechanically expanded such as with a balloon. It is also known thatstents of various designs may be plastically deformable as well aselastically deformable. The embodiments of the outer frame 120 presentedherein are not to be limited to a specific stent design or mode ofexpansion.

The outer frame 120 can comprise any metallic or polymeric biocompatiblematerial. For example, the outer frame 120 can comprise a material, suchas, but not limited to nitinol, cobalt-nickel alloy, stainless steel, orpolypropylene, acetyl homopolymer, acetyl copolymer, ePTFE, other alloysor polymers, or any other biocompatible material having adequatephysical and mechanical properties to function as described herein.

In accordance with embodiments, the outer frame 120 and/or leaflet frame130 can be configured to provide positive engagement with an implantsite to firmly anchor the prosthetic heart valve 100 to the site, asshown in FIG. 4A representing a transcatheter deployment of theprosthetic heart valve 100. In accordance with an embodiment, the outerframe 120 can comprise a sufficiently rigid frame having small elasticrecoil so as to maintain sufficient apposition against a tissue orifice150 to maintain position. In accordance with another embodiment, theouter frame 120 and/or leaflet frame 130 can be configured to expand toa diameter that is larger than a tissue orifice 150 so that whenprosthetic heart valve 100 expands into the tissue orifice 150, it canbe firmly seated therein. In accordance with another embodiment, theouter frame 120 can comprise one or more anchors (not shown) configuredto engage the implant site, such as a tissue orifice 150, to secure theprosthetic heart valve 100 to the implant site.

It is appreciated that other elements or means for coupling theprosthetic heart valve 100 to an implant site are anticipated. By way ofexample, but not limited thereto, other means, such as mechanical andadhesive means may be used to couple the prosthetic heart valve 100 to asynthetic or biological conduit.

Sewing Cuff

In accordance with a surgical valve 100 embodiment, the valve 100further comprises a sewing cuff 170 about a body frame outer surface 127in accordance with an embodiment, as shown in FIG. 4B. The sewing cuff170 is operable to provide structure that receives suture for couplingto the implant site. The sewing cuff 170 may comprise any suitablematerial, such as, but not limited to, double velour polyester. Thesewing cuff 170 may be located circumferentially around a perimeter ofthe base frame 120. Sewing cuffs are known in the art.

Leaflet Frame

Referring again to FIGS. 1C and 2B, the leaflet frame 130 is a generallytubular member defining a plurality of leaflet windows 137 coupledtogether by connecting elements 139, in accordance with an embodiment.The leaflet frame 130 comprises a leaflet frame first end 138 a and aleaflet frame second end 138 b opposite the leaflet frame first end 138a. The leaflet frame 130 comprises a leaflet frame outer surface 132 aand a leaflet frame inner surface 132 b opposite the outer surface 132a, as shown in FIG. 5A. The leaflet frame first end 138 a and theleaflet frame second end 138 b define a generally zigzag configurationto facilitate flexion about flex points 136 such as which facilitatescompression and expansion between different diameters for compressiononto a delivery device and expansion by a balloon for the transcathetervalve 100 embodiments, as generally explained for the outer frame 120.As will be discussed later, the surgical prosthetic heart valve 100embodiment may or may not have the zigzag configuration since thesurgical prosthetic heart valve 100 may be of a fixed diameter and neednot be operable to compress and re-expand.

The leaflet frame 130 may be referred to in a general sense as a stentor a frame.

The leaflet frame 130 defines a predetermined repeating pattern as shownin FIG. 2B, in accordance with an embodiment. The leaflet frame 130defines three interconnected leaflet windows 137 having a substantiallytriangular shape. Each of the leaflet windows 137 include two leafletwindow sides 133, a leaflet window base 134, and a leaflet window top135. In this embodiment, the leaflet window base 134 defines a flexpoint 136 which will be described further below. A leaflet window side133 and leaflet window top 135 of one leaflet window 137 isinterconnected with a leaflet window side 133 of an adjacent leafletwindow 137.

The leaflet frame 130 defines any number of features and geometricshapes that facilitate substantially uniform circumferential compressionand expansion. The leaflet frame 130 may comprise a cut tube, or anyother element suitable for the particular purpose. The leaflet frame 130may be etched, cut, laser cut, or stamped into a tube or a sheet ofmaterial, with the sheet then formed into a substantially cylindricalstructure. Alternatively, an elongated material, such as a wire,bendable strip, or a series thereof, can be bent or braided and formedinto a substantially cylindrical structure wherein the walls of thecylinder comprise an open framework that is compressible to a smallerdiameter in a generally uniform and circumferential manner andexpandable to a larger diameter.

The leaflet frame 130 can comprise any metallic or polymericbiocompatible material. For example, the leaflet frame 130 can comprisea material, such as, but not limited to nitinol, cobalt-nickel alloy,stainless steel, or polypropylene, acetyl homopolymer, acetyl copolymer,ePTFE, other alloys or polymers, or any other biocompatible materialhaving adequate physical and mechanical properties to function asdescribed herein.

As will be described in more detail below, a film 160 is disposed overeach of the three leaflet windows 137 to form a leaflet 140. Furtherembodiments will be described below wherein the leaflet window 137defines shapes other than a substantially triangular shape, including,but not limited to a parabolic shape and a trapezoidal shape, with andwithout a leaflet window top 135, suitable for a particular purpose ofan embodiment of a surgical and transcatheter valve 100.

FIGS. 7A and 7B are side views of alternative embodiments of the leafletframe 130 a, 130 b wherein the leaflet frame has been longitudinally cutand laid open to better illustrate the elements of the leaflet frame.The leaflet frame 130 a includes leaflet windows 137 a having asubstantially triangular shape defining a pointed leaflet window base134 a. The leaflet frame 130 b includes leaflet windows 137 b having asubstantially triangular shape defining a flat leaflet window base 134b. The flat leaflet window base 134 b may be used to define the leafletbase.

FIGS. 8A-8C are side views of alternative embodiments of the leafletframe 130 c-130 e wherein the leaflet frame has been longitudinally cutand laid open to better illustrate the elements of the leaflet frame.The leaflet frame 130 c includes leaflet windows 137 c having asubstantially triangular shape defining a pointed leaflet window base134 c. The leaflet frame 130 d includes leaflet windows 137 d having asubstantially parabolic shape defining a rounded leaflet window base 134d. The flat leaflet window base 134 b may be used to define the leafletbase. The leaflet frame 130 e includes leaflet windows 137 e having asubstantially triangular shape defining a pointed leaflet window base134 c but not having a leaflet window top.

FIG. 8d is a side view of an alternative embodiment of the leaflet frame130 f wherein the leaflet frame 130 f has been longitudinally cut andlaid open to better illustrate the elements of the leaflet frame. Theleaflet frame 130 f includes leaflet windows 137 f having asubstantially isosceles trapezoid shape defining a flat leaflet windowbase 134 f. The flat leaflet window base 134 f may be used to define theleaflet base. In accordance with other embodiments of the prostheticvalve, each leaflet 140 f has substantially the shape of an isoscelestrapezoid having two leaflet sides 141 f, a leaflet base 142 f and afree edge 143 f opposite the leaflet base, wherein the two leaflet sidesdiverge from the leaflet base, wherein the leaflet base is substantiallyflat, as shown in dashed lines in FIG. 8 d.

FIG. 8e is a side view of an alternative embodiment of the leaflet frame130 g wherein the leaflet frame 130 g has been longitudinally cut andlaid open to better illustrate the elements of the leaflet frame. Theleaflet frame 130 g includes leaflet windows 137 g having asubstantially isosceles trapezoid shape defining a flat leaflet windowbase 134 f. The flat leaflet window base 134 g may be used to define theleaflet base. In accordance with other embodiments of the prostheticvalve, each leaflet 140 g has substantially the shape of an isoscelestrapezoid having two leaflet sides 141 g, a leaflet base 142 g and afree edge 143 g opposite the leaflet base, wherein the two leaflet sidesdiverge from the leaflet base, wherein the leaflet base is substantiallyflat, as shown in dashed lines in FIG. 8 e.

The frame comprises a plurality of spaced apart leaflet windows 137 feach leaflet attachment zone defines substantially an isosceles triangleinterconnected by a base element 138 f, wherein each leaflet window sideis defined by a side of one triangle and a side of an adjacent triangle,and wherein each leaflet window base is defined by the base element 138f.

FIG. 7A is a representation of another embodiment of a leaflet frame 130a unrolled to a flat orientation. The leaflet frame 130 a comprisesframe elements 139 suitable for affecting compression and expansion aswould be needed for intravascular placement. The leaflet window 137 a isdefined by two leaflet window sides 133 a that meet at a leaflet windowbase 134 a. A leaflet 140 is shown in dashed line to represent where theleaflet 140 is located within the leaflet window 137 a. The leafletsides 141 are coupled to the leaflet window sides 133 a and the leafletbase 143 is coupled to the leaflet window base 134 a.

FIG. 7B is a representation of another embodiment of a leaflet frame 130b unrolled to a flat orientation. The leaflet window 137 b is defined bytwo leaflet window sides 133 b that meet at a leaflet window base 134 bthat is elongated and horizontal with the valve axis. A leaflet 140 isshown in dashed line to represent where the leaflet 140 is locatedwithin the leaflet window 137 a. The leaflet sides 141 are coupled tothe leaflet window sides 133 a and the leaflet base 143 b is coupled tothe leaflet window base 134 a. The leaflet window base 134 b is flatsuch that the leaflet bends from a flat base during opening and closing.

FIG. 8A is a representation of another embodiment of a leaflet frame 130c unrolled to a flat orientation. The leaflet frame 130 c comprisesframe elements 139 suitable for affecting compression and expansion aswould be needed for intravascular placement. The leaflet window 137 c isdefined by two leaflet window sides 133 c that meet at a leaflet windowbase 134 c. A leaflet 140 is shown in dashed line to represent where theleaflet 140 is located within the leaflet window 137 c. The leafletsides 141 are coupled to the leaflet window sides 133 c and the leafletbase 143 c is coupled to the leaflet window base 134 c.

FIG. 8B is a representation of another embodiment of a leaflet frame 130d unrolled to a flat orientation. The leaflet frame 130 d comprisesframe elements 139 suitable for affecting compression and expansion aswould be needed for intravascular placement. The leaflet window 137 d isdefined by two leaflet window sides 133 d that meet at a leaflet windowbase 134 d. A leaflet 140 is shown in dashed line to represent where theleaflet 140 is located within the leaflet window 137 d. The leafletsides 141 are coupled to the leaflet window sides 133 d and the leafletbase 143 d is coupled to the leaflet window base 134 d. The leafletwindow sides 133 d define a parabolic shape.

FIG. 8C is a representation of another embodiment of a leaflet frame 130e unrolled to a flat orientation. The leaflet frame 130 e comprisesframe elements 139 suitable for affecting compression and expansion aswould be needed for intravascular placement. The leaflet window 137 e isdefined by two leaflet window sides 133 e that meet at a leaflet windowbase 134 e. A leaflet 140 is shown in dashed line to represent where theleaflet 140 is located within the leaflet window 137 e. The leafletsides 141 are coupled to the leaflet window sides 133 e and the leafletbase 143 e is coupled to the leaflet window base 134 a.

FIG. 8D is a side view of an alternative embodiment of the leaflet frame130 f wherein the leaflet frame 130 f has been longitudinally cut andlaid open to better illustrate the elements of the leaflet frame 130 f,of a valve substantially shown as the prosthetic heart valve 100 ofFIGS. 11A and 11B. A leaflet 140 f is shown in dashed line to representwhere the leaflet 140 f is located within the leaflet window 137 f, theleaflet window 137 f being defined by the leaflet window sides 133 f andthe leaflet window base 134 f. The two leaflet sides 141 f diverge fromthe leaflet base 143 f, wherein the leaflet base 143 f is substantiallyflat, with the leaflet free edge 142 f opposite the leaflet base 143 f,as shown in dashed lines in FIG. 8D. The leaflet frame 130 f furtherdefines commissure posts 136 from which the leaflet free edge 142 fextends.

FIG. 8E is a side view of an alternative embodiment of the leaflet frame130 g wherein the leaflet frame 130 g has been longitudinally cut andlaid open to better illustrate the elements of the leaflet frame 130 g.A leaflet 140 g is shown in dashed line to represent where the leaflet140 g is located within the leaflet window 137 g, the leaflet window 137g being defined by the leaflet window sides 133 g and the leaflet windowbase 134 g. Two leaflet sides 141 g diverge from the leaflet base 143 g,wherein the leaflet base 143 g is substantially flat, with the leafletfree edge 142 g opposite the leaflet base 143 g, as shown in dashedlines in FIG. 8E. The leaflet frame 130 g comprises a plurality ofleaflet frame elements defining a plurality of isosceles trianglesinterconnected by a leaflet window base 134 g defining leaflet windows137 g that define isosceles trapezoids. Each leaflet window side 133 gis defined by a side of one triangle and a side of an adjacent triangle.

FIG. 8F is a side view of an alternative embodiment of the leaflet frame130 h wherein the leaflet frame 130 h has been longitudinally cut andlaid open to better illustrate the elements of the leaflet frame 130 h.The leaflet frame 130 h comprises a base element 138 h and a pluralityof spaced apart spade elements 170 interconnected by the base element138 h. Each leaflet window 137 h is defined by a spade side 175 of onespade element 170 and a spade side 175 of an adjacent spade element 170,and wherein each leaflet window base 134 h is defined by the baseelement 138 h. The spade side 175 does not extend to the base element138 h. By virtue of the geometry, the leaflet 140 h, during opening andclosing, will bend about the spade side 175 and towards the base element138 h defining a partially frameless leaflet window 137 h where theleaflet 140 is not bending directly adjacent a frame element 139,defining an attachment zone 163. The leaflet base 143 h may be defined adistance away from the base element 138 h such that the leaflet base 143h is not bending directly adjacent the base element 138 h. A leafletbase 143 h that is not directly adjacent the base element 138 h isreferred herein as a virtual leaflet window base, virtual in the sensethat it is not defined directly by a frame element. In accordance withan embodiment of the prosthetic heart valve, each leaflet 140 h takesthe form of substantially the shape of an isosceles trapezoid having twoleaflet sides 141 h, a leaflet base 143 h and a leaflet free edge 142 hopposite the leaflet base 143 h, wherein the two leaflet sides 141 hdiverge from the leaflet base 143 h, wherein the leaflet base 143 h issubstantially flat, as shown in dashed lines in FIG. 8F.

In accordance with an embodiment, the leaflet frame comprises a framefirst end and a frame second end opposite the frame first end, theleaflet window having a shape determined, at least in part, by wrappinga two dimensional isosceles trapezoid onto the tubular shape of theframe, the isosceles trapezoid having a base and two sides that divergefrom the base, and wherein a side from adjacent isosceles trapezoidsmeet at the frame second end.

In another embodiment substantially as shown in FIG. 8F, a first layerof film 160 a is coupled to a leaflet frame inner surface 132 b of theleaflet frame 130 h and a second layer of film 160 b is coupled to aleaflet frame outer surface 132 a of the leaflet frame 130 h oppositefrom the leaflet frame inner surface 132 b. The first layer of film 160and the second layer of film 160 b are coupled together to define anattachment zone 163.

As previously discussed, the leaflet window base may be used to definethe leaflet base in accordance with embodiments. Also as previouslydiscussed, the leaflet base may be defined as a virtual leaflet base 143by a fold line 145 in the film 160 in the fold region spaced apart fromthe leaflet window base 134, as shown in FIGS. 1A and 1B, and shown bythe dashed lines in FIG. 2B. It is appreciated that there are manyembodiments of the outer frame having configurations suitable for theparticular purpose.

FIG. 10A is a side exploded view of another prosthetic heart valvecomprising a leaflet frame 1130 having a generally tubular shape and anouter frame 1120 having a generally tubular shape that are coupled by amechanical engagement member 1110, in accordance with anotherembodiment. FIG. 10B is an assembled view of the embodiment of FIG. 10A.

As previously discussed, the leaflet window base may be used to definethe leaflet base in accordance with embodiments. Also as previouslydiscussed, the leaflet base may be defined as a virtual leaflet base 143a by a fold line 145 in the film 160 in the fold region 144 spaced apartfrom the leaflet window base, as shown in FIGS. 1B and 2B. It isappreciated that there are many embodiments of the leaflet frame havingconfigurations suitable for the particular purpose.

In transcatheter prosthetic heart valve 100 embodiments, the leafletframe 130 is elastically, plastically, or both, compressible to obtain arelatively small diameter to accommodate percutaneous transcathetermounting and delivery.

The leaflet frame 130 may comprise, such as, but not limited to, anyelastically deformable metallic or polymeric biocompatible material, inaccordance with embodiments. The leaflet frame 130 may comprise ashape-memory material, such as nitinol, a nickel-titanium alloy. Othermaterials suitable for the leaflet frame 130 include, but are notlimited to, other titanium alloys, stainless steel, cobalt-nickel alloy,polypropylene, acetyl homopolymer, acetyl copolymer, other alloys orpolymers, or any other biocompatible material having adequate physicaland mechanical properties to function as a leaflet frame 130 asdescribed herein.

In accordance with an embodiment, the leaflet frame 130 and the outerframe 120 comprise a shape memory material operable to flex under loadand retain its original shape when the load is removed, thus allowingthe leaflet frame 130 and the outer frame 120 to self-expand from acompressed shape to a predetermined shape. The leaflet frame 130 and theouter frame 120 may comprise the same or different materials. Inaccordance with an embodiment the leaflet frame 130 is plasticallydeformable to be expanded by a balloon. In another embodiment, the outerframe 120 is elastically deformable so as to be self-expanding.

Film

The film 160 is generally any sheet-like material that is biologicallycompatible and configured to couple to leaflets to the leaflet frame, inaccordance with embodiments. It is understood that the term “film” isused generically for one or more biocompatible materials suitable for aparticular purpose. The leaflets 140 are also comprised of the film 160.

In accordance with an embodiment, the film 160 that is not of abiological source and that is sufficiently flexible and strong for theparticular purpose, such as a biocompatible polymer. In an embodiment,the film 160 comprises a biocompatible polymer that is combined with anelastomer, referred to as a composite.

It is also understood that the film 160 that is coupled to the outerframe 120 may not be the same film 160 that is coupled to the leafletframe 130, in accordance with embodiments. Details of various types offilm 160 are discussed below. In an embodiment, the film 160 may beformed from a generally tubular material to at least partially cover theouter frame 120 and the leaflet frame 130. The film 160 can comprise oneor more of a membrane, composite material, or laminate. Details ofvarious types of film 160 are discussed below.

Leaflet

Each leaflet window 137 is provided with a film 160, which is coupled toa portion of the leaflet window sides 133 with the film 160 defining aleaflet 140. Each leaflet 140 defines a leaflet free edge 142 and aleaflet base 143, in accordance with an embodiment. As will be describedbelow, it is anticipated that a plurality of embodiments of leaflet baseconfigurations may be provided. In accordance with an embodiment, thefilm 160 is coupled to a portion of the leaflet window sides 133 and tothe leaflet window base 134 where the leaflet 140 is defined by theportion of the leaflet window sides 133 and to the leaflet window base134. In accordance with another embodiment, the film 160 is coupled to aportion of the leaflet window sides 133 but not the leaflet window base134 of the leaflet frame 130 where the leaflet 140 is defined by theportion of the leaflet window sides 133 and to a virtual leaflet base1033 defined in a fold region as will be described below.

The shape of the leaflets 140 are defined in part by the shape of theleaflet window 137 and the leaflet free edge 142. As will be discussedbelow in accordance with an embodiment, the shape of the leaflets 140also depends in part on a process that induces a fold at the fold line145 to define a virtual leaflet base 143 a as will be described furtherbelow, so as to impart a predetermined shape to the leaflet 140. Sincehigh bending stresses are located at the leaflet base, defining avirtual leaflet base 143 a that is not bound by the leaflet window base134 may reduce the chance of tearing of the leaflet 140 at the leafletbase 143—leaflet window base 134 interface. It may also reduce bloodpooling and stagnation at the leaflet base as compared with a roundedleaflet base.

When the leaflets 140 are in a fully open position, the prosthetic heartvalve 100 presents a substantially circular valve orifice 102 as shownin FIG. 3A. Fluid flow is permitted through the valve orifice 102 whenthe leaflets 140 are in an open position.

As the leaflets 140 cycle between the open and closed positions, theleaflets 140 generally flex about the leaflet base 143 and the portionof the leaflet window sides 133 to which the leaflet are coupled. Whenthe prosthetic heart valve 100 is closed, generally about half of eachleaflet free edge 142 abuts an adjacent half of a leaflet free edge 142of an adjacent leaflet 140, as shown in FIG. 3B. The three leaflets 140of the embodiment of FIG. 3B meet at a triple point 148. The valveorifice 102 is occluded when the leaflets 140 are in the closed positionstopping fluid flow.

Referring to FIG. 3B, in accordance with an embodiment, each leaflet 140includes a central region 182 and two side regions 184 on opposite sidesof the central region 182. The central region 182 is defined by a shapesubstantially that of an isosceles triangle defined by two centralregion sides 183, the leaflet base 143 and the leaflet free edge 142.The two central region sides 183 converge from the leaflet base 143 tothe leaflet free edge 142. Each of the side regions 184 have a shapesubstantially that of a triangle and each are defined by one of thecentral region sides 183, one of the leaflet sides 141, and the leafletfree edge 142.

In accordance with an embodiment, each of the two side regions 184 andthe central region 182 are substantially planar when the prostheticheart valve 100 is in the closed position.

The leaflet 140 can be configured to actuate at a pressure differentialin the blood caused, for example, by the contraction of a ventricle oratrium of the heart, such pressure differential typically resulting froma fluid pressure building up on one side of the prosthetic heart valve100 when closed. As the pressure on an inflow side of the prostheticheart valve 100 rises above the pressure on the outflow side of theprosthetic heart valve 100, the leaflet 140 opens and blood flowstherethrough. As blood flows through the prosthetic heart valve 100 intoa neighboring chamber or blood vessel, the pressure equalizes. As thepressure on the outflow side of the prosthetic heart valve 100 risesabove the blood pressure on the inflow side of the prosthetic heartvalve 100, the leaflet 140 returns to the closed position generallypreventing the retrograde flow of blood through the inflow side of theprosthetic heart valve 100.

It is understood that the leaflet frame 130 may comprise any number ofleaflet windows 137, and thus leaflets 140, suitable for a particularpurpose, in accordance with embodiments. Leaflet frames 130 comprisingone, two, three or more leaflet windows 137 and corresponding leaflets140 are anticipated.

In accordance with an embodiment of a transcatheter prosthetic heartvalve 100, with reference to FIGS. 1D-1E, the prosthetic heart valve 100may be compressed into a collapsed configuration having a smallerdiameter and expanded into an expanded configuration so that theprosthetic heart valve 100 can be delivered via catheter in thecollapsed configuration and expanded upon deployment within the tissueorifice 150 as shown in FIG. 4A. The outer frame 120 can be operable torecover circumferential uniformity when transitioning from the collapsedconfiguration to the expanded configuration.

Leaflet Film

The film 160 that makes up the leaflet 140 can comprise any biologicaltissue or synthetic, biocompatible materials sufficiently compliant andflexible, such as a biocompatible polymer. In an embodiment, the leaflet140 comprises a biocompatible polymer that is combined with anelastomer, referred to as a composite. A material according to oneembodiment includes a composite material comprising an expandedfluoropolymer membrane, which comprises a plurality of spaces within amatrix of fibrils, and an elastomeric material. It should be appreciatedthat multiple types of fluoropolymer membranes and multiple types ofelastomeric materials can be combined to form a laminate while remainingwithin the scope of the present disclosure. It should also beappreciated that the elastomeric material can include multipleelastomers, multiple types of non-elastomeric components, such asinorganic fillers, therapeutic agents, radiopaque markers, and the likewhile remaining within the scope of the present disclosure.

In accordance with an embodiment, the composite material includes anexpanded fluoropolymer material made from porous ePTFE membrane, forinstance as generally described in U.S. Pat. No. 7,306,729 to Bacino.

The expandable fluoropolymer, used to form the expanded fluoropolymermaterial described, may comprise PTFE homopolymer. In alternativeembodiments, blends of PTFE, expandable modified PTFE and/or expandedcopolymers of PTFE may be used. Non-limiting examples of suitablefluoropolymer materials are described in, for example, U.S. Pat. No.5,708,044, to Branca, U.S. Pat. No. 6,541,589, to Baillie, U.S. Pat. No.7,531,611, to Sabol et al., U.S. patent application Ser. No. 11/906,877,to Ford, and U.S. patent application Ser. No. 12/410,050, to Xu et al.

The expanded fluoropolymer membrane can comprise any suitablemicrostructure for achieving the desired leaflet performance. Inaccordance with an embodiment, the expanded fluoropolymer comprises amicrostructure of nodes interconnected by fibrils, such as described inU.S. Pat. No. 3,953,566 to Gore. The fibrils radially extend from thenodes in a plurality of directions, and the membrane has a generallyhomogeneous structure. Membranes having this microstructure maytypically exhibit a ratio of matrix tensile strength in two orthogonaldirections of less than 2, and possibly less than 1.5.

In another embodiment, the expanded fluoropolymer membrane has amicrostructure of substantially only fibrils, as is generally taught byU.S. Pat. No. 7,306,729, to Bacino. The expanded fluoropolymer membranehaving substantially only fibrils, can possess a high surface area, suchas greater than 20 m²/g, or greater than 25 m²/g, and in someembodiments can provide a highly balanced strength material having aproduct of matrix tensile strengths in two orthogonal directions of atleast 1.5×10⁵ MPa², and/or a ratio of matrix tensile strengths in twoorthogonal directions of less than 4, and possibly less than 1.5.

The expanded fluoropolymer membrane can be tailored to have any suitablethickness and mass to achieve the desired leaflet performance. By way ofexample, but not limited thereto, the leaflet 140 comprises an expandedfluoropolymer membrane having a thickness of about 0.1 μm. The expandedfluoropolymer membrane can possess a mass per area of about 1.15 g/m².Membranes according to an embodiment of the invention can have matrixtensile strengths of about 411 MPa in the longitudinal direction and 315MPa in the transverse direction.

Additional materials may be incorporated into the pores or within thematerial of the membranes or in between layers of membranes to enhancedesired properties of the leaflet. Composite materials described hereincan be tailored to have any suitable thickness and mass to achieve thedesired leaflet performance. Composite materials according toembodiments can include fluoropolymer membranes and have a thickness ofabout 1.9 μm and a mass per area of about 4.1 g/m².

The expanded fluoropolymer membrane combined with elastomer to form acomposite material provides the elements of the present disclosure withthe performance attributes required for use in high-cycle flexuralimplant applications, such as prosthetic heart valve leaflets, invarious ways. For example, the addition of the elastomer can improve thefatigue performance of the leaflet by eliminating or reducing thestiffening observed with ePTFE-only materials. In addition, it mayreduce the likelihood that the material will undergo permanent setdeformation, such as wrinkling or creasing, that could result incompromised performance. In one embodiment, the elastomer occupiessubstantially all of the pore volume or space within the porousstructure of the expanded fluoropolymer membrane. In another embodimentthe elastomer is present in substantially all of the pores of the atleast one fluoropolymer layer. Having elastomer filling the pore volumeor present in substantially all of the pores reduces the space in whichforeign materials can be undesirably incorporated into the composite. Anexample of such foreign material is calcium that may be drawn into themembrane from contact with the blood. If calcium becomes incorporatedinto the composite material, as used in a prosthetic heart valveleaflet, for example, mechanical damage can occur during cycling openand closed, thus leading to the formation of holes in the leaflet anddegradation in hemodynamics.

In an embodiment, the elastomer that is combined with the ePTFE is athermoplastic copolymer of tetrafluoroethylene (TFE) and perfluoromethylvinyl ether (PMVE), such as described in U.S. Pat. No. 7,462,675 toChang et al. As discussed above, the elastomer is combined with theexpanded fluoropolymer membrane such that the elastomer occupiessubstantially all of the void space or pores within the expandedfluoropolymer membrane to form a composite material. This filling of thepores of the expanded fluoropolymer membrane with elastomer can beperformed by a variety of methods. In one embodiment, a method offilling the pores of the expanded fluoropolymer membrane includes thesteps of dissolving the elastomer in a solvent suitable to create asolution with a viscosity and surface tension that is appropriate topartially or fully flow into the pores of the expanded fluoropolymermembrane and allow the solvent to evaporate, leaving the filler behind.

In one embodiment, the composite material comprises three layers: twoouter layers of ePTFE and an inner layer of a fluoroelastomer disposedtherebetween. Additional fluoroelastomers can be suitable and aredescribed in U.S. Publication No. 2004/0024448 to Chang.

In another embodiment, a method of filling the pores of the expandedfluoropolymer membrane includes the steps of delivering the filler via adispersion to partially or fully fill the pores of the expandedfluoropolymer membrane.

In another embodiment, a method of filling the pores of the expandedfluoropolymer membrane includes the steps of bringing the porousexpanded fluoropolymer membrane into contact with a sheet of theelastomer under conditions of heat and/or pressure that allow elastomerto flow into the pores of the expanded fluoropolymer membrane.

In another embodiment, a method of filling the pores of the expandedfluoropolymer membrane includes the steps of polymerizing the elastomerwithin the pores of the expanded fluoropolymer membrane by first fillingthe pores with a prepolymer of the elastomer and then at least partiallycuring the elastomer.

After reaching a minimum percent by weight of elastomer, the leafletsconstructed from fluoropolymer materials or ePTFE generally performedbetter with increasing percentages of elastomer resulting insignificantly increased cycle lives. In one embodiment, the elastomercombined with the ePTFE is a thermoplastic copolymer oftetrafluoroethylene and perfluoromethyl vinyl ether, such as describedin U.S. Pat. No. 7,462,675 to Chang et al., and other references thatwould be known to those of skill in the art. Other biocompatiblepolymers which can be suitable for use in leaflet 140 include but arenot limited to the groups of urethanes, silicones(organopolysiloxanes),copolymers of silicon-urethane, styrene/isobutylene copolymers,polyisobutylene, polyethylene-co-poly(vinyl acetate), polyestercopolymers, nylon copolymers, fluorinated hydrocarbon polymers andcopolymers or mixtures of each of the foregoing.

Other Considerations

In accordance with an embodiment, the prosthetic heart valve can beconfigured to prevent interference with a heart conduction system by notcovering a bundle branch in the left ventricle when implanted, such asmight be encountered with an aortic valve replacement procedure. Forexample, the prosthetic heart valve can comprise a length of less thanabout 25 mm or less than about 18 mm. The prosthetic heart valve canalso comprise an aspect ratio of less than one, wherein the ratiodescribes the relationship between the length of the prosthetic heartvalve to the expanded, functional diameter. However, the prostheticheart valve can be constructed at any length and, more generally, anydesirable dimension.

In a transcatheter embodiment, in a collapsed state, the prostheticheart valve can have a collapsed profile that is less than about 35% ofthe expanded profile. For example, the prosthetic heart valve 100comprising a 26 mm expanded diameter can have a collapsed diameter ofless than about 8 mm, or less than about 6 mm. The percent difference indiameter is dependent on dimensions and materials of the prostheticheart valve and its various applications, and therefore, the actualpercent difference is not limited by this disclosure.

The prosthetic heart valve can further comprise a bio-active agent.Bio-active agents can be coated onto a portion or the entirety of thefilm 160 for controlled release of the agents once the prosthetic heartvalve is implanted. The bio-active agents can include, but are notlimited to, vasodilator, anti-coagulants, anti-platelet,anti-thrombogenic agents such as, but not limited to, heparin. Otherbio-active agents can also include, but are not limited to agents suchas, for example, anti-proliferative/antimitotic agents including naturalproducts such as vinca alkaloids (i.e. vinblastine, vincristine, andvinorelbine), paclitaxel, epidipodophyllotoxins (i.e. etoposide,teniposide), antibiotics (dactinomycin (actinomycin D) daunorubicin,doxorubicin and idarubicin), anthracyclines, mitoxantrone, bleomycins,plicamycin (mithramycin) and mitomycin, enzymes (L-asparaginase whichsystemically metabolizes L-asparagine and deprives cells which do nothave the capacity to synthesize their own asparagine); antiplateletagents such as G(GP) IIb/IIIa inhibitors and vitronectin receptorantagonists; anti-proliferative/antimitotic alkylating agents such asnitrogen mustards (mechlorethamine, cyclophosphamide and analogs,melphalan, chlorambucil), ethylenimines and methylmelamines(hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan,nitrosoureas (carmustine (BCNU) and analogs, streptozocin),trazenes-dacarbazinine (DTIC); anti-proliferative/antimitoticantimetabolites such as folic acid analogs (methotrexate), pyrimidineanalogs (fluorouracil, floxuridine, and cytarabine), purine analogs andrelated inhibitors (mercaptopurine, thioguanine, pentostatin and2-chlorodeoxyadenosine {cladribine}); platinum coordination complexes(cisplatin, carboplatin), procarbazine, hydroxyurea, mitotane,aminoglutethimide; hormones (i.e. estrogen); anti-coagulants (heparin,synthetic heparin salts and other inhibitors of thrombin); fibrinolyticagents (such as tissue plasminogen activator, streptokinase andurokinase), aspirin, dipyridamole, ticlopidine, clopidogrel, abciximab;antimigratory; antisecretory (breveldin); anti-inflammatory: such asadrenocortical steroids (cortisol, cortisone, fludrocortisone,prednisone, prednisolone, 6α-methylprednisolone, triamcinolone,betamethasone, and dexamethasone), non-steroidal agents (salicylic acidderivatives i.e. aspirin; para-aminophenol derivatives i.e.acetominophen; indole and indene acetic acids (indomethacin, sulindac,and etodalac), heteroaryl acetic acids (tolmetin, diclofenac, andketorolac), arylpropionic acids (ibuprofen and derivatives), anthranilicacids (mefenamic acid, and meclofenamic acid), enolic acids (piroxicam,tenoxicam, phenylbutazone, and oxyphenthatrazone), nabumetone, goldcompounds (auranofin, aurothioglucose, gold sodium thiomalate);immunosuppressives: (cyclosporine, tacrolimus (FK-506), sirolimus(rapamycin), azathioprine, mycophenolate mofetil); angiogenic agents:vascular endothelial growth factor (VEGF), fibroblast growth factor(FGF); angiotensin receptor blockers; nitric oxide donors; anti-senseoligionucleotides and combinations thereof; cell cycle inhibitors, mTORinhibitors, and growth factor receptor signal transduction kinaseinhibitors; retenoids; cyclin/CDK inhibitors; HMG co-enzyme reductaseinhibitors (statins); and protease inhibitors.

Transcatheter Delivery System

In an embodiment, with reference to FIG. 4A, a valve delivery system 500comprises a prosthetic heart valve 100 having a collapsed configurationand an expanded configuration as previously described and an elongatedflexible catheter 480, such as a balloon catheter, configured to deploythe prosthetic heart valve 100 via catheter. The catheter 480 cancomprise a balloon to expand the prosthetic heart valve 100 and/or ifrequired, to touch up the prosthetic heart valve 100 to ensure properseating. The prosthetic heart valve 100 can be mounted to the distalsection of the catheter 480 for delivery through the vasculature. Inorder to hold the prosthetic heart valve in a collapsed configuration onthe catheter 480, the valve delivery system may further comprise aremovable sheath (not shown) to closely fit over the transcatheterprosthetic heart valve 100.

A method of delivery can comprise the steps of radially compressing aprosthetic heart valve into its collapsed configuration onto the distalend of an elongate flexible catheter having proximal and distal ends;delivering the prosthetic heart valve to a tissue orifice, such as anative aortic valve orifice, via a transfemoral or transapical route,and expanding the prosthetic heart valve into the tissue orifice. Theprosthetic heart valve can be expanded by inflating a balloon.

A method of delivery can comprise the steps of radially compressing aprosthetic heart valve into its collapsed configuration, onto the distalsection of an elongated flexible catheter having proximal and distalends. A restraint, which can be connected to a tether that passesthrough the orifice of the prosthetic heart valve and the lumen of thecatheter, is fitted around the commissure posts of the prosthetic heartvalve. The prosthetic heart valve is then delivered to a native valveorifice, such as a native aortic valve orifice, via a route of deliveryand expanded into the native orifice. The route of delivery can comprisea transfemoral or transapical route. The prosthetic heart valve can beexpanded by inflating a balloon.

SURGICAL EMBODIMENTS

It is appreciated that the embodiments of the prosthetic heart valve 100may be surgically implanted rather than using transcatheter techniques.Embodiments of a surgically implanted prosthetic heart valve 100 may besubstantially the same as those described above, with the addition of asewing cuff 190 adjacent to the outer frame outer surface 126 a, shownin FIG. 4B, in accordance with an embodiment. The sewing cuff 190, whichis well known in the art, is operable to provide structure that receivessuture for coupling the prosthetic heart valve 100 to an implant site,such as the tissue orifice 150. The sewing cuff 190 may comprise anysuitable material, such as, but not limited to, double velour polyester.The sewing cuff 190 may be located circumferentially around the outerframe 120.

Method of Making

Embodiments described herein also pertain to a method of making theprosthetic heart valve 100 embodiments as described herein. In order tomake the various embodiments, a cylindrical mandrel 710 can be used.With reference to FIG. 9A, the mandrel 710 comprises a structural formoperable to receive the outer frame 120 thereon.

With reference to FIGS. 9A and 9B, an embodiment of a method of making aprosthetic heart valve 100 comprises the steps of wrapping a first layerof film 160, e.g., a composite as described herein, into a tubular formabout the mandrel 710; placing the leaflet frame 130 and outer frame 120over the first layer of film 160, as shown in FIG. 9A; forming a secondlayer of film 160 over the leaflet frame 130 and the outer frame 120;thermally setting the assembly; cutting the film 160 across the leafletwindow top within the leaflet window 137, masking with release material170 a portion of the film 160 in the leaflet window that defines theleaflet 140 to prevent further bonding of leaflet 140 during subsequentprocessing steps; wrapping a second layer of film 160 into a tubularform over the 120, and over the first layer of film 160; thermal settingthe assembly; remove the assembly from the mandrel.

Embodiments described herein also pertain to a method of making theprosthetic heart valve 200 embodiments as described herein. In order tomake the various embodiments, a cylindrical mandrel 710 can be used.With reference to FIG. 12, the mandrel 710 comprises a structural formoperable to receive the leaflet frame 130 thereon. An embodiment of amethod of making a prosthetic heart valve 200 comprises the steps ofwrapping a first layer of film 160, e.g., a composite as describedherein, into a tubular form about the mandrel 710; placing the leafletframe 130 over the first layer of film 160, as shown in FIG. 12; forminga second layer of film 160 over the leaflet frame 130; thermally settingthe assembly; receiving the assembly over a cutting mandrel 712 as shownin FIGS. 13A and 13B; cutting the film 160 across the leaflet window topwithin the leaflet window 137, resulting in the prosthetic heart valve200 of FIGS. 11A and 11B. FIG. 11A is a side view of an embodiment of aprosthetic heart valve and FIG. 11B is a perspective view of theembodiment of the prosthetic heart valve of FIG. 11A. In FIGS. 11A and11B the leaflets 140 are shown slightly open as when held by the cuttingmandrel 712. It is understood that a fully closed prosthetic heart valve200 will have the leaflet free edges 142 of the leaflets 140 comingtogether to coapt under the influence of downstream fluid pressure whichresults in closing the valve to prevent downstream blood from flowingretrograde through the valve.

EXAMPLES Example 1

A prosthetic heart valve was produced having polymeric leaflets formedfrom a composite material having an expanded fluoropolymer membrane andan elastomeric material and joined between two collapsible metallicframes.

The leaflet frame and outer frame were laser machined from a length ofSS316LVM tube hard tempered with an outside diameter of 23.0 mm and awall thickness of 0.65 mm in the shape shown illustratively andgenerally indicated in FIG. 9A. The leaflet frame 130 and outer frame120 were electro-polished resulting in 0.0127 mm material removal fromeach surface and leaving the edges rounded.

Fluorinated ethylene propylene (FEP) powder (Daikin America, OrangeburgN.Y.) was then applied to the leaflet frame 130 and outer frame 120.More specifically, the FEP powder was stirred to form an airborne“cloud” in an enclosed blending apparatus, such as a standard kitchentype blender, while the leaflet frame and outer frame were suspended inthe cloud. The leaflet frame and outer frame were exposed to the FEPpowder cloud until a uniform layer of powder was adhered to the entiresurface of the leaflet frame and outer frame. The leaflet frame andouter frame were then subjected to a thermal treatment by placing it ina forced air oven set to 320° C. for approximately three minutes. Thiscaused the powder to melt and adhere as a thin coating over the entireleaflet frame and outer frame. The leaflet frame and outer frame wereremoved from the oven and left to cool to room temperature.

Initial Assembly and Thermal Process Cycle

A 21 mm diameter vented metal cylindrical mandrel having a diametercorresponding to the inner diameter of the leaflet frame 130 and outerframe 120 was helically wrapped with sintered ePTFE fiber. A thin filmof type 1 (ASTM D3368) FEP was constructed using melt extrusion andstretching. The type 1 (ASTM D3368) FEP film was about 40 μm thick andwas about 7.7 cm wide. The mandrel was helically wrapped with one layerof this type 1 FEP film over the sintered ePTFE fiber only in the regionof outer frame.

The mandrel was radially wrapped with five layers of an ePTFE membranewith an FEP coating towards the mandrel. The ePTFE membrane wasmanufactured according to the general teachings described in U.S. Pat.No. 7,306,729. The ePTFE membrane had a mass per area of 2.3 g/m², abubble point of 101.5 MPa, a thickness of about 356 nm, a matrix tensilestrength of 319 MPa in the longitudinal direction and 407 MPa in thetransverse direction.

The mandrel was helically wrapped with one layer of type 1 FEP film.

The diameter of the leaflet frame and outer frame were expanded slightlyand received on the wrapped mandrel with approximately a 10 mm spacebetween them, rotational alignment was not necessary.

The leaflet frame, outer frame and the space therebetween were helicallywrapped with 1 layer of type 1 FEP film.

The leaflet frame, outer frame and the space therebetween that willbecome the bridge portion 162 and the fold region 144, as shown in FIG.2B, were circumferentially wrapped with 5 layers of the same ePTFEmembrane with an FEP coating as described above with the coating towardthe mandrel.

The wrapped leaflet frame, outer frame and the space therebetween werewrapped with several layers of an ePTFE membrane imbibed with apolyimide material referred to as a release liner.

A substantially nonporous ePTFE membrane was configured into a cylinderand placed over the assembly, referred to as sacrificial tube. SinteredePTFE fiber was used to seal both ends of the sacrificial tube againstthe mandrel.

The assembly, including the mandrel, was heated in an oven capable ofapplying pneumatic pressure external to the sacrificial tube describedabove and while maintaining a vacuum internal to the mandrel for 40 minsuch that the mandrel temperature reached approximately 360° C. Theassembly was removed from the oven and allowed to cool to roomtemperature while still pressurized and under vacuum.

The sacrificial tube and release liner was removed. The sintered ePTFEfiber was removed to release the frame assembly from the mandrel.

The polymeric material was trimmed and removed from the leaflet windowsof the leaflet frame. The ends of each leaflet frame and outer framewere circumferentially trimmed by a scalpel.

Intermediate Assembly and Thermal Process Cycle

An unsintered 15 mm diameter ePTFE tube was disposed on a 21.5 mm ventedmetal mandrel. Two layers of a substantially nonporous ePTFE membranewith a FEP coating was circumferentially wrapped on the mandrel with thecoating side towards the mandrel. The wrapped mandrel was placed in aconvection oven set to 320° C. and heated for 20 min. The ePTFE andsubstantially nonporous ePTFE membrane combined to serve as a releaseliner and was perforated to communicate pressure between the vent holesin the mandrel.

The leaflet frame was disposed onto the vented metal mandrel and ventholes were made in the apertures of the leaflet frame over the mandrelvent holes.

A leaflet material was then prepared. A membrane of ePTFE wasmanufactured according to the general teachings described in U.S. Pat.No. 7,306,729. The ePTFE membrane had a mass per area of 0.452 g/m², athickness of about 508 nm, a matrix tensile strength of 705 MPa in thelongitudinal direction and 385 MPa in the transverse direction. Thismembrane was imbibed with a fluoroelastomer. The copolymer consistsessentially of between about 65 and 70 weight percent perfluoromethylvinyl ether and complementally about 35 and 30 weight percenttetrafluoroethylene.

The fluoroelastomer was dissolved in Novec HFE7500 (3M, St Paul, Minn.)in a 2.5% concentration. The solution was coated using a Mayer bar ontothe ePTFE membrane (while being supported by a polypropylene releasefilm) and dried in a convection oven set to 145° C. for 30 seconds.After two coating steps, the final ePTFE/fluoroelastomer or compositehad a mass per area of 1.75 g/m², 29.3% fluoropolymer by weight, a domeburst strength of about 8.6 KPa, and thickness of 0.81 μm.

The following test methods were used to characterize the ePTFE layersand the multi-layered composite. The thickness was measured with aMutitoyo Snap Gage Absolute, 12.7 mm (0.50″) diameter foot, ModelID-C112E, Serial #10299, made in Japan. The density was determined by aweight/volume calculation using an Analytical Balance Mettler PM400 NewJersey, USA. The force to break and tensile strengths were measuredusing an Instron Model #5500R Norwood, Mass., load cell 50 kg, gagelength=25.4 cm, crosshead speed=25 mm/minute (strain rate=100% perminute) with flat faced jaws. Unless otherwise noted, these test methodswere used to generate the data in subsequent examples.

Ten layers of the composite leaflet material were wrapped around theleaflet frame with an elastomer rich side of the composite facingtowards the mandrel. In exemplary embodiments, the composite material isoriented to have a predetermined matrix tensile strength along adirection generally perpendicular with the longitudinal axis of thecombined tool assembly. More specifically, the predetermined matrixtensile strength is about 705 MPa.

The mandrel was radially wrapped with one layer of a substantiallynonporous ePTFE membrane with an FEP coating towards the mandrel with aspacing 8 mm from the base of the leaflet frame. The ePTFE membrane wasmanufactured according to the general teachings described in U.S. Pat.No. 7,306,729. The ePTFE membrane had a mass per area of about 11 g/m²,a thickness of about 5.5 μm, a matrix tensile strength of 310 MPa in thelongitudinal direction and 103 MPa in the transverse direction.

A Kapton® (EI DuPont de Nemours, Inc., Wilmington, Del.) polyimide filmacting as a mask was wrapped over the substantially nonporous ePTFEmembrane with an FEP coating layer.

The outer frame was placed on the mandrel with 10 mm spacing between theleaflet frame and the outer frame. The leaflet frame and the outer framewere aligned such that the longitudinal outer frame posts were collinearwith the leaflet frame commissure posts.

The leaflet frame and outer frame were wrapped with 24 layers of thecomposite leaflet material described earlier with an elastomer rich sideof the composite facing towards the mandrel. In exemplary embodiments,the composite material is oriented to have a predetermined matrixtensile strength along a direction generally perpendicular with thelongitudinal axis of the combined tool assembly. More specifically, thepredetermined matrix tensile strength is about 705 MPa.

The final leaflet was comprised of 29.3% fluoropolymer by weight with athickness of approximately 27 μm. Each leaflet had 34 layers of thecomposite and a ratio of thickness/number of layers of 0.8 μm.

The mandrel was again radially wrapped with one layer of a substantiallynonporous ePTFE membrane with an FEP coating towards the mandrel with aspacing 8 mm from the base of the leaflet frame.

The assembly was wrapped with several layers of the sacrificial releaseliner. A sacrificial tube was placed over the assembly and sinteredePTFE fiber was used to seal both ends of the sacrificial tube againstthe mandrel.

The assembly was processed in an oven capable of applying pneumaticpressure external to the sacrificial material configured into a tubedescribed above and while maintaining a vacuum internal to the tube for25 min such that the mandrel temperature reached approximately 330° C.The assembly was removed from the oven and allowed to cool to roomtemperature while still pressurized and under vacuum.

The sacrificial tube and liner were removed from the frame assembly andthe frame assembly was removed from the mandrel. The Kapton® mask wasremoved.

A scalpel was used to circumferentially trim the leaflet free edge ofeach leaflet and the distal end of leaflet frame.

Final Assembly and Thermal Process Cycle

The outer frame was radially expanded to a 24 mm diameter using atapered mandrel.

A release liner as described above was placed on a 21.5 mm ventedmandrel.

Three Kapton® masks were cut to the shape of leaflet window with a 30 mmtapered extension.

The leaflet frame and outer frame with leaflet material were placed ontothe mandrel and the tapered extensions of the Kapton® masks wereinserted under the top ring of the leaflet frame from the trimmed endand were advanced axially until the masks aligned with the leafletwindow.

The leaflet frame was wrapped with 2 layers of the type 1 FEP film.

A hot iron was used to remove the FEP film from the leaflet windowregion by melting it away from the perimeter and to tack the FEP film inall regions of leaflet frame outside the masks.

Vent holes were made within all the leaflet frame apertures and in thepolymer tube region connecting the inner frame and outer frame.

While holding the leaflet frame in place, the outer frame was coaxiallydisposed over the leaflet frame by telescopically inverting the bridgeportion of the contiguous tube.

The entire frame assembly was circumferentially wrapped with onesubstantially nonporous ePTFE membrane with an FEP coating towards themandrel.

The assembly was wrapped with several layers of the sacrificial releaseliner. A sacrificial tube was placed over the assembly and sinteredePTFE fiber was used to seal both ends of the sacrificial tube againstthe mandrel.

The assembly was processed in an oven capable of applying pneumaticpressure external to the sacrificial material configured into a tubedescribed above and while maintaining a vacuum internal to the tube for25 min such that the mandrel temperature reached approximately 330° C.The assembly was removed from the oven and allowed to cool to roomtemperature while still pressurized and under vacuum.

The frame assembly was removed from the mandrel.

A scalpel was used to circumferentially trim each end of leaflet frame.

The Kapton was rotationally peeled away from inside the outer frame andaway from leaflets.

Using scissors, both ends of the leaflet frame were trimmed to followframe contour.

The resulting prosthetic heart valve 100 includes leaflets 140 formedfrom a composite material with more than one fluoropolymer layer havinga plurality of pores and an elastomer present in substantially all ofthe pores of the more than one fluoropolymer layer. Each leaflet 140 ismovable between a closed position, shown in FIG. 3B, in which blood issubstantially prevented from flowing through the valve assembly, and anopen position, shown in FIG. 3A, in which blood is allowed to flowthrough the valve assembly. Thus, the leaflets 140 of the prostheticheart valve 100 cycle between the closed and open positions generally toregulate blood flow direction in a human patient.

The performance of the prosthetic heart valve leaflets was characterizedon a real-time pulse duplicator that measured typical anatomicalpressures and flows across the prosthetic heart valve. The flowperformance was characterized by the following process:

The valve assembly was potted into a silicone annular ring (supportstructure) to allow the valve assembly to be subsequently evaluated in areal-time pulse duplicator. The potting process was performed accordingto the recommendations of the pulse duplicator manufacturer (ViVitroLaboratories Inc., Victoria BC, Canada).

The potted valve assembly was then placed into a real-time left heartflow pulse duplicator system. The flow pulse duplicator system includedthe following components supplied by VSI Vivitro Systems Inc., VictoriaBC, Canada: a Super Pump, Servo Power Amplifier Part Number SPA 3891; aSuper Pump Head, Part Number SPH 5891B, 38.320 cm² cylinder area; avalve station/fixture; a Wave Form Generator, TriPack Part Number TP2001; a Sensor Interface, Part Number VB 2004; a Sensor AmplifierComponent, Part Number AM 9991; and a Square Wave Electro Magnetic FlowMeter, Carolina Medical Electronics Inc., East Bend, N.C., USA.

In general, the flow pulse duplicator system uses a fixed displacement,piston pump to produce a desired fluid flow through the prosthetic heartvalve under test.

The heart flow pulse duplicator system was adjusted to produce thedesired flow (5 L/min), mean pressure (15 mmHg), and simulated pulserate (70 bpm). The prosthetic heart valve under test was then cycled forabout 5 to 20 minutes.

Pressure and flow data were measured and collected during the testperiod, including right ventricular pressures, pulmonary pressures, flowrates, and pump piston position.

Parameters used to characterize a prosthetic heart valve are effectiveorifice area and regurgitant fraction. The effective orifice area (EOA),which can be calculated as follows: EOA(cm²)=Q_(rms)/(51.6*(ΔP)^(1/2))where Q_(rms) is the root mean square systolic/diastolic flow rate(cm³/s) and ΔP is the mean systolic/diastolic pressure drop (mmHg).

Another measure of the hydrodynamic performance of a prosthetic heartvalve is the regurgitant fraction, which is the amount of fluid or bloodregurgitated through the prosthetic heart valve divided by the strokevolume.

The hydrodynamic performance measured values were; EOA=2.06 cm², andregurgitant fraction=8.2%.

Example 2

Another prosthetic heart valve was made as described in Example 1 withthe following exceptions.

Initial Assembly and Thermal Process Cycle

The diameter of the leaflet frame and outer frame were expanded slightlyand received on the wrapped mandrel with 16 mm space between them,rotational alignment of the leaflet frame and outer frame was made.

Final Assembly and Thermal Process Cycle

A scalpel was used to cut above the mechanical linking tab. The tab wasdeformed to link the leaflet frame to the outer frame.

The resulting prosthetic heart valve 100 includes leaflets 140 formedfrom a composite material with more than one fluoropolymer layer havinga plurality of pores and an elastomer present in substantially all ofthe pores of the more than one fluoropolymer layer. Each leaflet 140 ismovable between a closed position, shown in FIG. 3B, in which blood issubstantially prevented from flowing through the valve assembly, and anopen position, shown in FIG. 3A, in which blood is allowed to flowthrough the valve assembly. Thus, the leaflets 140 of the prostheticheart valve 100 cycle between the closed and open positions generally toregulate blood flow direction in a human patient.

The hydrodynamic performance was measured. The performance values were;EOA=2.3 cm² and regurgitant fraction=11.8%.

Numerous characteristics and advantages have been set forth in thepreceding description, including various alternatives together withdetails of the structure and function of the devices and/or methods. Thedisclosure is intended as illustrative only and as such is not intendedto be exhaustive. It will be evident to those skilled in the art thatvarious modifications can be made, especially in matters of structure,materials, elements, components, shape, size and arrangement of partsincluding combinations within the principles of the disclosure, to thefull extent indicated by the broad, general meaning of the terms inwhich the appended claims are expressed. To the extent that thesevarious modifications do not depart from the spirit and scope of theappended claims, they are intended to be encompassed therein.

Example 3

(Single Leaflet Frame Prosthetic Heart Valve)

In exemplary embodiments, a prosthetic heart valve having polymericleaflets formed from a composite material having an expandedfluoropolymer membrane and an elastomeric material and joined to asemi-rigid, non-collapsible metallic frame, and further a having strainrelief was constructed according to the following process:

A leaflet frame was laser machined from a length of MP35N cobaltchromium tube hard tempered with an outside diameter of 26.0 mm and awall thickness of 0.6 mm in the shape. The leaflet frame waselectro-polished resulting in 0.0127 mm material removal from eachsurface and leaving the edges rounded. The leaflet frame was exposed toa surface roughening step to improve adherence of leaflets to theleaflet frame. The leaflet frame was cleaned by submersion in anultrasonic bath of acetone for approximately five minutes. The entiremetal leaflet frame surface was then subjected to a plasma treatmentusing equipment (e.g. PVA TePLa America, Inc Plasma Pen, Corona, Calif.)and methods commonly known to those having ordinary skill in the art.This treatment also served to improve the wetting of the fluorinatedethylene propylene (FEP) adhesive.

FEP powder (Daikin America, Orangeburg N.Y.) was then applied to theleaflet frame. More specifically, the FEP powder was stirred to form anairborne “cloud” in an enclosed blending apparatus, such as a standardkitchen type blender, while the leaflet frame is suspended in the cloud.The leaflet frame was exposed to the FEP powder cloud until a layer ofpowder was adhered to the entire surface of the leaflet frame. Theleaflet frame was then subjected to a thermal treatment by placing it ina forced air oven set to 320° C. for approximately three minutes. Thiscaused the powder to melt and adhere as a thin coating over the entireleaflet frame. The leaflet frame was removed from the oven and left tocool to approximately room temperature.

The strain relief was attached to the leaflet frame in the followingmanner. A thin (122 μm) walled sintered 15 mm diameter ePTFE tube wasdisposed on a 24.5 mm vented metal mandrel by stretching radially over atapered mandrel. Two layers of a substantially nonporous ePTFE membranewith a continuous FEP coating was circumferentially wrapped on themandrel with the FEP side towards the mandrel. The wrapped mandrel wasplaced in a convection oven set to 320° C. and heated for 20 min. TheePTFE and substantially nonporous ePTFE membrane combined to serve as aninner release liner and was perforated using a scalpel blade tocommunicate pressure between the vent holes in the mandrel. This entirerelease liner is removed in a later step.

A 5 cm length of the thick (990μ) walled partially sintered 22 mm innerdiameter ePTFE tube (density=0.3 g/cm³) was disposed onto the 24.5 mmvented metal mandrel with release liner. The ePTFE tube inner diameterwas enlarged by stretching it on a tapered mandrel to accommodate thelarger mandrel diameter.

A thin (4 μm) film of type 1 FEP (ASTM D3368) was constructed using meltextrusion and stretching. One layer of the FEP was wrapped over the 5 cmlength of the ePTFE tube.

The FEP powder coated leaflet frame was disposed onto the vented metalmandrel generally in the middle of the 5 cm span of ePTFE tube and FEPfilm.

One layer of the FEP was wrapped over the leaflet frame and 5 cm lengthof the ePTFE tube.

A second 5 cm length of the 990 μm thick/22 mm inner diameter ePTFE tubewas disposed onto the assembly layered onto 24.5 mm vented metal mandrelby stretching its radius over a tapered mandrel to accommodate thelarger construct diameter.

A substantially nonporous ePTFE membrane was configured into a cylinderat a diameter larger than the construct and placed over the assembly,referred to as sacrificial tube. Sintered ePTFE fiber (e.g. Gore Rastex®Sewing Thread, Part #S024T2, Newark Del.) was used to seal both ends ofthe sacrificial tube against the mandrel.

The assembly, including the mandrel, was heated in a convection oven(temperature set point of 390° C.) capable of applying pneumaticpressure of 100 psi external to the sacrificial tube described abovewhile maintaining a vacuum internal to the mandrel. The assembly wascooked for 40 min such that the mandrel temperature reachedapproximately 360° C. (as measured by a thermocouple direct contact withthe inner diameter of the mandrel). The assembly was removed from theoven and allowed to cool to approximately room temperature while stillunder 100 psi pressure and vacuum.

The sacrificial tube was then removed. Approximately 30 psi of pressurewas applied to the internal diameter of the mandrel to assist in removalof the assembly. The inner release liner was peeled away from theinternal diameter of the assembly by inverting the liner and axiallypulling it apart.

The polymeric material was trimmed with a scalpel and removed from theleaflet windows and bottom of the leaflet frame leaving approximately0.5 to 1.0 mm of material overhang.

A leaflet material was then prepared. A membrane of ePTFE wasmanufactured according to the general teachings described in U.S. Pat.No. 7,306,729. The ePTFE membrane had a mass per area of 0.452 g/m², athickness of about 508 nm, a matrix tensile strength of 705 MPa in thelongitudinal direction and 385 MPa in the transverse direction. Thismembrane was imbibed with a fluoroelastomer. The copolymer consistsessentially of between about 65 and 70 weight percent perfluoromethylvinyl ether and complementally about 35 and 30 weight percenttetrafluoroethylene.

The fluoroelastomer was dissolved in Novec HFE7500 (3M, St Paul, Minn.)in a 2.5% concentration. The solution was coated using a mayer bar ontothe ePTFE membrane (while being supported by a polypropylene releasefilm) and dried in a convection oven set to 145° C. for 30 seconds.After 2 coating steps, the final ePTFE/fluoroelastomer or composite hada mass per area of 1.75 g/m², 29.3% fluoropolymer by weight, a domeburst strength of about 8.6 KPa, and thickness of 0.81 μm.

The final leaflet was comprised of 28.22% fluoropolymer by weight with athickness of 50.3 μm. Each leaflet had 26 layers of the composite and aratio of thickness/number of layers of 1.93 μm.

The resulting prosthetic heart valve 200 includes leaflets 140 formedfrom a composite material with more than one fluoropolymer layer havinga plurality of pores and an elastomer present in substantially all ofthe pores of the more than one fluoropolymer layer. Each leaflet 140 ismovable between a closed position, shown illustratively in FIG. 11D, inwhich blood is substantially prevented from flowing through the valveassembly, and an open position, shown illustratively in FIG. 11C, inwhich blood is allowed to flow through the prosthetic heart valve 200.Thus, the leaflets 140 of the prosthetic heart valve 200 cycle betweenthe closed and open positions generally to regulate blood flow directionin a human patient.

The hydrodynamic performance was measured prior to accelerated weartesting. The performance values were; EOA=2.4 cm² and regurgitantfraction=11.94%.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present embodimentswithout departing from the spirit or scope of the embodiments. Thus, itis intended that the present embodiments cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed:
 1. A prosthetic valve, comprising: a support structurehaving a tubular shape; and a plurality of leaflets, each leaflet havinga first leaflet side, a second leaflet side opposite the first leafletside, a leaflet base, and a leaflet free edge opposite the leaflet base,each leaflet base being coupled to the support structure and an entirelength of each leaflet base being flat such that in cross section eachleaflet base defines a continuous line of attachment of the leaflet baseto the support structure in an alpha plane, each of the plurality ofleaflets being trapezoidal-shaped.
 2. The prosthetic valve of claim 1,wherein the support structure defines a plurality of leaflet windowscorresponding to the plurality of leaflets, each leaflet window having aleaflet window base that is flat in the alpha plane.
 3. The prostheticvalve of claim 1, wherein the support structure defines a plurality oftrapezoidal-shaped leaflet windows corresponding to the plurality ofleaflets.
 4. The prosthetic valve of claim 1, wherein each leaflet basedefines a straight line perpendicular to a longitudinal axis of theprosthetic valve.
 5. The prosthetic valve of claim 1, wherein anentirety of each leaflet base is coupled to the support structure. 6.The prosthetic valve of claim 1, wherein the support structure includesan expandable leaflet frame.
 7. The prosthetic valve of claim 1, whereinthe support structure includes an inner valve frame and an outer valveframe.
 8. The prosthetic valve of claim 1, wherein the support structureincludes a valve frame and a covering.
 9. The prosthetic valve of claim1, wherein each of the leaflets is formed of polymeric film material.10. A prosthetic valve, comprising: a support structure having a tubularshape and defining a plurality of leaflet windows, each leaflet windowdefining a first side, a second side, and a base, each of the pluralityof leaflet windows being trapezoidal-shaped; and a plurality of leafletsextending from the plurality of leaflet windows, each leaflet having afirst leaflet side coupled to the first side of a respective leafletwindow of one of the leaflet windows, a second leaflet side opposite thefirst leaflet side that is coupled to the second side of the respectiveleaflet window, a leaflet base that is coupled to the base of therespective leaflet window, and a leaflet free edge opposite the leafletbase, the leaflet base being flat and defining a continuous line ofattachment of the leaflet base to the base of the respective leafletwindow.
 11. The prosthetic valve of claim 10, wherein each of theplurality of leaflets is trapezoidal-shaped.
 12. The prosthetic valve ofclaim 10, wherein each leaflet base defines a straight lineperpendicular to a longitudinal axis of the prosthetic valve.
 13. Theprosthetic valve of claim 10, wherein an entirety of each leaflet baseis coupled to the support structure.
 14. The prosthetic valve of claim10, wherein the support structure includes an expandable leaflet frame.15. The prosthetic valve of claim 10, wherein the support structureincludes an inner valve frame and an outer valve frame.
 16. Theprosthetic valve of claim 10, wherein the support structure includes avalve frame and a covering.
 17. The prosthetic valve of claim 10,wherein each of the leaflets is formed of polymeric film material. 18.The prosthetic valve of claim 10, wherein each of the leaflets istrapezoidal-shaped and includes a planar central region.
 19. Aprosthetic valve, comprising: a support structure having a tubular shapeand defining a plurality of leaflet windows, each leaflet windowdefining a first side, a second side, and a base, the support structureincluding an inner valve frame and an outer valve frame; and a pluralityof leaflets extending from the plurality of leaflet windows, eachleaflet having a first leaflet side coupled to the first side of arespective leaflet window of one of the leaflet windows, a secondleaflet side opposite the first leaflet side that is coupled to thesecond side of the respective leaflet window, a leaflet base that iscoupled to the base of the respective leaflet window, and a leaflet freeedge opposite the leaflet base, the leaflet base being flat and defininga continuous line of attachment of the leaflet base to the base of therespective leaflet window.
 20. The prosthetic valve of claim 19, whereineach of the plurality of leaflets is trapezoidal-shaped.